Coastal Fog As a System: Defining an Interdisciplinary Research Agenda (Invited)

Science.gov (United States)

Weathers, K. C.

2013-12-01

Fog is a graphic and charismatic phenomenon that is commonplace in coastal geographies around the globe. Some of the first concerns about fog and human health arose over 50 years ago in foggy cities around the world, such as London and Los Angeles, where thousands of excess deaths have been attributed to the presence of acidic fog particles. Further, the mere presence of fog also results in airplane, ship, and automobile traffic delays and accidents, especially in coastal areas. In many Pacific coastal systems, fog is the primary--sometimes the only--source of water, it is a fundamental moderator of local and regional climate, and it influences productivity of near-coast ecosystems. In recent years fog has been identified as a vector for limiting nutrients (e.g., nitrogen and phosphorus), pollutants (e.g., mercury), and microbes (including human pathogens), all of whose origin is thought to be biologically controlled in the ocean. Researchers have also started inquiring into the importance of fog in modulating weather as well as local, regional and, global climate dynamics. However, from its formation in marine systems to deposition in terrestrial systems, understanding the fog system is an intellectual and interdisciplinary challenge that, to date, has gone unmet. This is in part because the fog system is complex: it involves feedbacks and coupling between physical, chemical, and biological systems in the ocean, atmosphere, and near-coast terrestrial systems. In addition, its formation is the result of global processes, yet its distribution as well as its impacts are local, and extremely spatially and temporally heterogeneous within and across landscapes. Here we describe a systems approach and framework for understanding the controls on fog formation as well as feedbacks to its formation, dissipation, distribution, flows, and stocks or pools. In addition, an interdisciplinary research agenda for coastal fog as a system will be described based on the outcome of a

Coastal erosion management in Accra: Combining local knowledge and empirical research

Directory of Open Access Journals (Sweden)

Kwasi Appeaning Addo

2016-11-01

Full Text Available Coastal erosion along the Accra coast has become a chronic phenomenon that threatens both life and property. The issue has assumed a centre stage of national debate in recent times because of its impact on the coastal communities. Lack of reliable geospatial data hinders effective scientific investigations into the changing trends in the shoreline position. However, knowledge about coastal erosion, by the local people, and how far the shoreline has migrated inland over time is high in the coastal communities in Accra. This opens a new chapter in coastal erosion research to include local knowledge of the local settlers in developing sustainable coastal management. This article adopted a scientific approach to estimate rate of erosion and tested the results against perceived erosion trend by the local settlers. The study used a 1974 digital topographic map and 1996 aerial photographs. The end point rate statistical method in DSAS was used to compute the rates of change. The short-term rate of change for the 22-year period under study was estimated as -0.91 m/annum ± 0.49 m/annum. It was revealed that about 79% of the shoreline is eroding, while the remaining 21% is either stabilised or accreting. It emerged, from semi-structured interviews with inhabitants in the Accra coastal communities, that an average of about 30 m of coastal lands are perceived to have been lost to erosion for a period of about 20 years. This translates to a historic rate of change of about 1.5 m/year, which corroborates the results of the scientific study. Again this study has established that the local knowledge of the inhabitants, about coastal erosion, can serve as reliable information under scarcity of scientific data for coastal erosion analyses in developing countries.

Research progress of III-V laser bonding to Si

Science.gov (United States)

Bo, Ren; Yan, Hou; Yanan, Liang

2016-12-01

The vigorous development of silicon photonics makes a silicon-based light source essential for optoelectronics' integration. Bonding of III-V/Si hybrid laser has developed rapidly in the last ten years. In the tireless efforts of researchers, we are privileged to see these bonding methods, such as direct bonding, medium adhesive bonding and low temperature eutectic bonding. They have been developed and applied to the research and fabrication of III-V/Si hybrid lasers. Some research groups have made remarkable progress. Tanabe Katsuaki of Tokyo University successfully implemented a silicon-based InAs/GaAs quantum dot laser with direct bonding method in 2012. They have bonded the InAs/GaAs quantum dot laser to the silicon substrate and the silicon ridge waveguide, respectively. The threshold current of the device is as low as 200 A/cm2. Stevan Stanković and Sui Shaoshuai successfully produced a variety of hybrid III-V/Si laser with the method of BCB bonding, respectively. BCB has high light transmittance and it can provide high bonding strength. Researchers of Tokyo University and Peking University have realized III-V/Si hybrid lasers with metal bonding method. We describe the progress in the fabrication of III-V/Si hybrid lasers with bonding methods by various research groups in recent years. The advantages and disadvantages of these methods are presented. We also introduce the progress of the growth of III-V epitaxial layer on silicon substrate, which is also a promising method to realize silicon-based light source. I hope that readers can have a general understanding of this field from this article and we can attract more researchers to focus on the study in this field.

Use of modular amphibious vehicles for conducting research in coastal zone

Science.gov (United States)

Zeziulin, Denis; Makarov, Vladimir; Belyaev, Alexander; Beresnev, Pavel; Kurkin, Andrey

2016-04-01

The project aims to create workable running systems of research complexes, moving along the bottom of coastal areas (in shallow waters) for investigation of waves, currents, sediment transport; investigation of ecosystems and biodiversity assessment of organisms; inspection and monitoring environmental conditions and anthropogenic load on nature; bathymetric studies. With all the variety of functional capabilities of modern robotic systems, possibilities of their application in the context of the study of coastal zones are extremely limited. Conducting research using aerial vehicles is limited to safety conditions of flight. Use of floating robotic systems in environmental monitoring and ecosystem research is only possible in conditions of relatively «soft» wave climate of the coastal zone. For these purposes, there are special amphibians such as remote-controlled vehicle Surf Rover [Daily, William R., Mark A. Johnson, and Daniel A. Oslecki. «Initial Development of an Amphibious ROV for Use in Big Surf.» Marine Technology Society 28.1 (1994): 3-10. Print.], mobile system MARC-1 [«The SPROV'er.» Florida Institute of Technology: Department of Marine and. Environmental Systems. Web. 05 May 2010.]. The paper describes methodological approaches to the selection of the design parameters of a new system.

The roles of large top predators in coastal ecosystems: new insights from long term ecological research

Science.gov (United States)

Rosenblatt, Adam E.; Heithaus, Michael R.; Mather, Martha E.; Matich, Philip; Nifong, James C.; Ripple, William J.; Silliman, Brian R.

2013-01-01

During recent human history, human activities such as overhunting and habitat destruction have severely impacted many large top predator populations around the world. Studies from a variety of ecosystems show that loss or diminishment of top predator populations can have serious consequences for population and community dynamics and ecosystem stability. However, there are relatively few studies of the roles of large top predators in coastal ecosystems, so that we do not yet completely understand what could happen to coastal areas if large top predators are extirpated or significantly reduced in number. This lack of knowledge is surprising given that coastal areas around the globe are highly valued and densely populated by humans, and thus coastal large top predator populations frequently come into conflict with coastal human populations. This paper reviews what is known about the ecological roles of large top predators in coastal systems and presents a synthesis of recent work from three coastal eastern US Long Term Ecological Research (LTER) sites where long-term studies reveal what appear to be common themes relating to the roles of large top predators in coastal systems. We discuss three specific themes: (1) large top predators acting as mobile links between disparate habitats, (2) large top predators potentially affecting nutrient and biogeochemical dynamics through localized behaviors, and (3) individual specialization of large top predator behaviors. We also discuss how research within the LTER network has led to enhanced understanding of the ecological roles of coastal large top predators. Highlighting this work is intended to encourage further investigation of the roles of large top predators across diverse coastal aquatic habitats and to better inform researchers and ecosystem managers about the importance of large top predators for coastal ecosystem health and stability.

Coastal remote sensing – towards integrated coastal research and management

CSIR Research Space (South Africa)

Lück-Vogel, Melanie

2012-10-01

Full Text Available coastal resources and anthropogenic infrastructure for a safer future. What is the role of remote sensing? The coastal zone connects terrestrial biophysical systems with marine systems. Some marine ecosystems cannot function without intact inland... for the development of sound integrated management solutions. To date, however, remote sensing applications usually focus on areas landward from the highwater line (?terrestrial? remote sensing), while ?marine? remote sensing does not pay attention to the shallow...

Defense Coastal/Estuarine Research Program 2 (DCERP2)

Science.gov (United States)

2013-05-01

Assessing TMDL effectiveness using flow-adjusted concentrations:  A case study of the Neuse River , North Carolina. Environmental Science & Technology 37...activities, and data collection in the NRE Basin and New River by local stakeholder groups. Defense Coastal/Estuarine Research Program (DCERP) Monitoring...relationships between light penetration and solids/chl a levels. ArcGIS and spatial statistics will be used to estimate average bathymetric areas

Defense Coastal/Estuarine Research Program (DCERP) Strategic Plan

Science.gov (United States)

2007-09-01

availability to phytoplankton in the water column, as well as to benthic microalgae, macroalgae , and seagrasses in bottom waters (Gallegos et al., 2005...further another of MCBCL’s key management objectives for meeting the requirements of the CWA. How wetlands may be utilized for water treatment ...Regulations Appendix B Prioritized list of MCBCL’s conservation and water quality needs Defense Coastal/Estuarine Research Program (DCERP) Strategic

Coastal marine pollution and toxicology : overview of current research and future needs

International Nuclear Information System (INIS)

Zubir Din

1996-01-01

The contents are marine pollution and toxicology studies at Universiti Sains Malaysia, their facilities, and research projects have been done on this subject. In coastal pollution monitoring and baseline studies, the emphasis have been on determination of levels of trace-metals in the coastal marine environment, in relation to other physico-chemical parameters. The future needs and goals of marine pollution and toxicology studies in Malaysia also discussed

Coastal marine pollution and toxicology : overview of current research and future needs

Energy Technology Data Exchange (ETDEWEB)

Din, Zubir [Science Univ. of Malaysia, Minden, Pulau Pinang (Malaysia). Centre for Marine and Coastal Studies

1997-12-31

The contents are marine pollution and toxicology studies at Universiti Sains Malaysia, their facilities, and research projects have been done on this subject. In coastal pollution monitoring and baseline studies, the emphasis have been on determination of levels of trace-metals in the coastal marine environment, in relation to other physico-chemical parameters. The future needs and goals of marine pollution and toxicology studies in Malaysia also discussed.

How can cloud processing enable generation of new knowledge through multidisciplinary research? The case of Co-ReSyF for coastal research

Science.gov (United States)

Politi, Eirini; Scarrott, Rory; Tuohy, Eimear; Terra Homem, Miguel; Caumont, Hervé; Grosso, Nuno; Mangin, Antoine; Catarino, Nuno

2017-04-01

According to the United Nations Environment Programme (UNEP), half the world's population lives within 60 km of the sea, and three-quarters of all large cities are located on the coast. Natural hazards and changing coastal processes due to environmental and climate change and intensified human activities, can affect coastal regions in many ways, such as coastal inundation, erosion and marine pollution among others, causing loss of life and degradation of vulnerable coastal and marine habitats. To fully understand how the environment is changing across transitional landscapes, such as the coastal zone, a combination of methods and disciplines is required. Geospatial approaches that harness global and regional datasets, along with new generation remote sensing products and climate variables, can help characterise trajectories of change in coastal systems and improve our knowledge and understanding of complex processes. However, such approaches often require Big Data and often Real-Time (RT) datasets to ensure timeliness in risk prediction, assessment and management. In addition, the task of identifying suitable datasets from the plethora of data repositories and sources that currently exist can be challenging, even for experienced researchers. As geospatial datasets continue to increase in quantity and quality, processing has become slower and demanding of better, often faster, computing facilities. To address these issues, an EU-funded project is developing an online platform to bring geospatial data, processing and coastal communities together in a collaborative cloud-based environment. The European Commission (EC) H2020 Coastal Water Research Synergy Framework (Co-ReSyF) project is developing a platform based on cloud computing to maximise processing effort and task orchestration. Users will be able to access, view and process satellite data, and visualise and share their outputs on the platform. This will allow faster processing and innovative data synergies, by

Research Progress on Preparation for Biomass-based SiC Ceramic

Directory of Open Access Journals (Sweden)

CUI He-shuai

2017-08-01

Full Text Available Silicon carbide (SiC ceramics prepared by the conventional process has excellent properties and wide application prospects, but the increased cost of high-temperature preparation process restricts its further development. In contrast, the abundant porous structure of biomass makes itself to be ideal replacement of SiC ceramic prepared at low temperature. This paper reviewed the structure characteristics, preparation methods, pyrolysis mechanism and influence parameters of biomass-based SiC ceramic, and eventually explored the current problems and development trends of the pretreatment of carbon source and silicon source, the pyrolysis process and the application research on the preparation for biomass-based SiC ceramic.

Research on a Micro-Nano Si/SiGe/Si Double Heterojunction Electro-Optic Modulation Structure

Directory of Open Access Journals (Sweden)

Song Feng

2018-01-01

Full Text Available The electro-optic modulator is a very important device in silicon photonics, which is responsible for the conversion of optical signals and electrical signals. For the electro-optic modulator, the carrier density of waveguide region is one of the key parameters. The traditional method of increasing carrier density is to increase the external modulation voltage, but this way will increase the modulation loss and also is not conducive to photonics integration. This paper presents a micro-nano Si/SiGe/Si double heterojunction electro-optic modulation structure. Based on the band theory of single heterojunction, the barrier heights are quantitatively calculated, and the carrier concentrations of heterojunction barrier are analyzed. The band and carrier injection characteristics of the double heterostructure structure are simulated, respectively, and the correctness of the theoretical analysis is demonstrated. The micro-nano Si/SiGe/Si double heterojunction electro-optic modulation is designed and tested, and comparison of testing results between the micro-nano Si/SiGe/Si double heterojunction micro-ring electro-optic modulation and the micro-nano Silicon-On-Insulator (SOI micro-ring electro-optic modulation, Free Spectrum Range, 3 dB Bandwidth, Q value, extinction ratio, and other parameters of the micro-nano Si/SiGe/Si double heterojunction micro-ring electro-optic modulation are better than others, and the modulation voltage and the modulation loss are lower.

Extending NASA Research Results to Benefit Society: Rapid Prototyping for Coastal Applications

Science.gov (United States)

Glorioso, Mark V.; Miller, Richard L.; Hall, Callie M.; McPherson, Terry R.

2006-01-01

The mission of the NASA Applied Sciences Program is to expand and accelerate the use of NASA research results to benefit society in 12 application areas of national priority. ONe of the program's major challenges is to perform a quick, efficient, and detailed review (i.e., prototyping) of the large number of combinations of NASA observations and results from Earth system models that may be used by a wide range of decision support tools. A Rapid Prototyping Capacity (RPC) is being developed to accelerate the use of NASA research results. Here, we present the conceptual framework of the Rapid Prototyping Capacity within the context of quickly assessing the efficacy of NASA research results and technologies to support the Coastal Management application. An initial RPC project designed to quickly evaluate the utility of moderate-resolution MODIS products for calibrating/validating coastal sediment transport models is also presented.

South Baltic representative coastal field surveys, including monitoring at the Coastal Research Station in Lubiatowo, Poland

Science.gov (United States)

Ostrowski, Rafał; Schönhofer, Jan; Szmytkiewicz, Piotr

2016-10-01

The paper contains a brief description of selected investigations carried out in the south Baltic coastal zone, with the particular focus on the history and recent activities conducted at the Coastal Research Station in Lubiatowo (CRS Lubiatowo), Poland. These activities comprise field investigations of nearshore hydrodynamic, lithodynamic, and morphodynamic processes. The study area is a sandy multi-bar shore with a mild slope, much exposed to the impact of waves approaching from NW-NE sector. The shore has a dissipative character which means that the wave energy is subject to gradual dissipation in the nearshore zone and only a small part of this energy is reflected by the shore. Due to the big wind fetch in N-NNE direction, the location of CRS Lubiatowo is favourable to registration of the maximum values of parameters of hydrodynamic and morphodynamic processes which occur in the Baltic during extreme storms.

Research on ZnO/Si heterojunction solar cells

Science.gov (United States)

Chen, Li; Chen, Xinliang; Liu, Yiming; Zhao, Ying; Zhang, Xiaodan

2017-06-01

We put forward an n-ZnO/p-Si heterojunction solar cell model based on AFORS-HET simulations and provide experimental support in this article. ZnO:B (B-doped ZnO) thin films deposited by metal-organic chemical vapor deposition (MOCVD) are planned to act as electrical emitter layer on p-type c-Si substrate for photovoltaic applications. We investigate the effects of thickness, buffer layer, ZnO:B affinity and work function of electrodes on performances of solar cells through computer simulations using AFORS-HET software package. The energy conversion efficiency of the ZnO:B(n)/ZnO/c-Si(p) solar cell can achieve 17.16% ({V}{oc}: 675.8 mV, {J}{sc}: 30.24 mA/cm2, FF: 83.96%) via simulation. On a basis of optimized conditions in simulation, we carry out some experiments, which testify that the ZnO buffer layer of 20 nm contributes to improving performances of solar cells. The influences of growth temperature, thickness and diborane (B2H6) flow rates are also discussed. We achieve an appropriate condition for the fabrication of the solar cells using the MOCVD technique. The obtained conversion efficiency reaches 2.82% ({V}{oc}: 294.4 mV, {J}{sc}: 26.108 mA/cm2, FF: 36.66%). Project supported by the State Key Development Program for Basic Research of China (Nos. 2011CBA00706, 2011CBA00707), the Tianjin Applied Basic Research Project and Cutting-Edge Technology Research Plan (No. 13JCZDJC26900), the Tianjin Major Science and Technology Support Project (No. 11TXSYGX22100), the National High Technology Research and Development Program of China (No. 2013AA050302), and the Fundamental Research Funds for the Central Universities (No. 65010341).

Coastal Inlet Model Facility

Data.gov (United States)

Federal Laboratory Consortium — The Coastal Inlet Model Facility, as part of the Coastal Inlets Research Program (CIRP), is an idealized inlet dedicated to the study of coastal inlets and equipped...

Strategy for sustainability of the Joint European Research Infrastructure Network for Coastal Observatories - JERICO

OpenAIRE

Puillat, Ingrid; Farcy, Patrick; Durand, Dominique; Petihakis, George; Morin, Pascal; Kriegger, Magali; Petersen, Wilhelm; Tintoré, Joaquin; Sorensen, Kai; Sparnocchia, Stefania; Wehde, Henning

2015-01-01

The JERICO European research infrastructure (RI) is integrating several platform types i.e. fixed buoys, piles, moorings, drifters, Ferryboxes, gliders, HF radars, coastal cable observatories and the associated technologies dedicated to the observation and monitoring of the European coastal seas. The infrastructure is to serve both the implementation of European marine policies and the elucidation of key scientific questions through dedicated observation and monitoring plans. It includes obse...

The European water framework directive: A challenge for nearshore, coastal and continental shelf research

Science.gov (United States)

Borja, Ángel

2005-09-01

The European Water Framework Directive (WFD) establishes a framework for the protection of groundwater, inland surface waters, estuarine waters, and coastal waters. The WFD constitutes a new view of the water resources management in Europe because, for the first time, water management is: (i) based mainly upon biological and ecological elements, with ecosystems being at the centre of the management decisions; (ii) applied to European water bodies, as a whole; and (iii) based upon the whole river basin, including also the adjacent coastal area. Although the marine water bodies affected by the WFD relate to only 19.8% of the whole of the European continental shelf, its application constitutes a challenge and an opportunity in nearshore, coastal and continental shelf research. This contribution highlights some of the main tasks and the research to be undertaken in the coming years, proposing investigations into: typologies; physico-chemical processes; indicator species; reference conditions; integration of the quality assessment; methodologies in determining ecological status, etc.

Atomization of U3Si2 for research reactor fuel

International Nuclear Information System (INIS)

Kim, C.K.; Kim, K.H.; Lee, C.T.; Kuk, I.H.

1995-01-01

Rotating disk atomization technique is applied to KMRR (Korea Multi-purpose Research Reactor) fuel fabrication. A rotating disk atomizer is designed and manufactured locally and U-4.0 wt. % Si alloy powders are produced. The atomized powders are heat-treated to transform into U 3 Si and the mixture of U 3 Si and Al are extruded to fuel meat. Most of the atomized powders are spherical in shape. The microstructure of the powder is fine due to the rapid solidification. The time required for peritectoid reaction is reduced due to the fine microstructures and the resultant U 3 Si grain size is finer than ever obtained from ingot process. The mechanical properties of the fuel meat are improved: yield strength about 30 %, tensile strength 10% and elongation 250 % increased. (author)

A meta-analysis of plant facilitation in coastal dune systems: responses, regions, and research gaps.

Science.gov (United States)

Castanho, Camila de Toledo; Lortie, Christopher J; Zaitchik, Benjamin; Prado, Paulo Inácio

2015-01-01

Empirical studies in salt marshes, arid, and alpine systems support the hypothesis that facilitation between plants is an important ecological process in severe or 'stressful' environments. Coastal dunes are both abiotically stressful and frequently disturbed systems. Facilitation has been documented, but the evidence to date has not been synthesized. We did a systematic review with meta-analysis to highlight general research gaps in the study of plant interactions in coastal dunes and examine if regional and local factors influence the magnitude of facilitation in these systems. The 32 studies included in the systematic review were done in coastal dunes located in 13 countries around the world but the majority was in the temperate zone (63%). Most of the studies adopt only an observational approach to make inferences about facilitative interactions, whereas only 28% of the studies used both observational and experimental approaches. Among the factors we tested, only geographic region mediates the occurrence of facilitation more broadly in coastal dune systems. The presence of a neighbor positively influenced growth and survival in the tropics, whereas in temperate and subartic regions the effect was neutral for both response variables. We found no evidence that climatic and local factors, such as life-form and life stage of interacting plants, affect the magnitude of facilitation in coastal dunes. Overall, conclusions about plant facilitation in coastal dunes depend on the response variable measured and, more broadly, on the geographic region examined. However, the high variability and the limited number of studies, especially in tropical region, indicate we need to be cautious in the generalization of the conclusions. Anyway, coastal dunes provide an important means to explore topical issues in facilitation research including context dependency, local versus regional drivers of community structure, and the importance of gradients in shaping the outcome of net

A meta-analysis of plant facilitation in coastal dune systems: responses, regions, and research gaps

Directory of Open Access Journals (Sweden)

Camila de Toledo Castanho

2015-02-01

Full Text Available Empirical studies in salt marshes, arid, and alpine systems support the hypothesis that facilitation between plants is an important ecological process in severe or ‘stressful’ environments. Coastal dunes are both abiotically stressful and frequently disturbed systems. Facilitation has been documented, but the evidence to date has not been synthesized. We did a systematic review with meta-analysis to highlight general research gaps in the study of plant interactions in coastal dunes and examine if regional and local factors influence the magnitude of facilitation in these systems. The 32 studies included in the systematic review were done in coastal dunes located in 13 countries around the world but the majority was in the temperate zone (63%. Most of the studies adopt only an observational approach to make inferences about facilitative interactions, whereas only 28% of the studies used both observational and experimental approaches. Among the factors we tested, only geographic region mediates the occurrence of facilitation more broadly in coastal dune systems. The presence of a neighbor positively influenced growth and survival in the tropics, whereas in temperate and subartic regions the effect was neutral for both response variables. We found no evidence that climatic and local factors, such as life-form and life stage of interacting plants, affect the magnitude of facilitation in coastal dunes. Overall, conclusions about plant facilitation in coastal dunes depend on the response variable measured and, more broadly, on the geographic region examined. However, the high variability and the limited number of studies, especially in tropical region, indicate we need to be cautious in the generalization of the conclusions. Anyway, coastal dunes provide an important means to explore topical issues in facilitation research including context dependency, local versus regional drivers of community structure, and the importance of gradients in shaping

Researchers focus attention on coastal response to climate change

Science.gov (United States)

Anderson, John; Rodriguez, Antonio; Fletcher, Charles; Fitzgerald, Duncan

The world's population has been steadily migrating toward coastal cities, resulting in severe stress on coastal environments. But the most severe human impact on coastal regions may lie ahead as the rate of global sea-level rise accelerates and the impacts of global warming on coastal climates and oceanographic dynamics increase [Varekamp and Thomas, 1998; Hinrichsen, 1999; Goodwin et al., 2000]. Little is currently being done to forecast the impact of global climate change on coasts during the next century and beyond. Indeed, there are still many politicians, and even some scientists, who doubt that global change is a real threat to society.

The Coastal Ocean Prediction Systems program: Understanding and managing our coastal ocean

International Nuclear Information System (INIS)

1990-01-01

This document is a compilation of summaries of papers presented at the Coastal Ocean Prediction Systems workshop. Topics include; marine forecasting, regulatory agencies and regulations, research and application models, research and operational observing, oceanic and atmospheric data assimilation, and coastal physical processes

Coastal fog and low cloud spatial patterns: do they indicate potential biodiversity refugia?

Science.gov (United States)

Torregrosa, A.

2016-12-01

Marine fog and low clouds transfer water and nutrients to coastal ecosystems through advection from the ocean and reduce heat effects by reflecting incoming shortwave radiation. These effects are known to benefit many species, vegetation communities, and habitats such as coastal redwood trees and their understory, maritime chaparral, and coastal streams harboring endangered salmon species. The California floristic region is the highest ranked hotspot in the U.S. and ranked 7th of 35 biodiversity hotspots worldwide in terms of the percent of its plant species that are found nowhere else (endemic). Many environmental drivers have been identified as contributing to California's remarkably high endemism and biodiversity, however, coastal low clouds have not typically been included. This could be due to the lack of data such as high resolution maps of coastal low cloud occurrence or the lack of long term records. Using a recent analysis of hourly National Weather Service satellite data, a stability index (SI) for coastal fog and low cloud cover was derived using two measures of variation and average summertime cloud cover to quantify long term spatial stability trends. Several discrete spatial clumps were identified that had both high temporal stability and high coastal low cloud cover. These areas show a strong correlation with a specific topographic landscape configuration with respect to wind direction. Point occurrence distribution maps of endemic coastal species were overlain with the SI to explore spatial correlation. The federally endangered species that showed very high spatial correlation included Yadon's Rein-orchid (Piperia yadonii), Monterey Spineflower (Chorizanthe pungens var. pungens), and Seaside Bird's-beak (Cordylanthus rigidus ssp. littoralis). Current estimated range maps are not consistent with the SI results suggesting a need to update estimated ranges. Biodiversity measures are being investigated in these areas to explore the hypothesis that they

Spatio-temporal variability in hydro-chemical characteristics of coastal waters of Salimpur, Chittagong along the Bay of Bengal

Directory of Open Access Journals (Sweden)

Avijit Talukder

2016-04-01

Full Text Available Diverse seasonal characteristics of hydro-chemical parameters in the coastal zone are significantly related to aquaculture development. In this paper, general water quality condition derived from laboratory analysis from the coastal waters of Salimpur, Chittagong is presented. Samples were collected from onshore and offshore site of two adjacent coastal locations named as North Salimpur (experimental location and South Kattoli (control during a monsoon and a dry season spanning 2013-14. The spatio-temporal variability of studied parameters were found as air temperature 26.5-32.5 ˚C, water temperature 23-33 °C, pH 7.1-7.9, DO 4.29-7.11 mg/L, BOD 1.10-3.25 mg/L, salinity 1.6-21 ppt, EC 3.40-35.68 mS/cm, TDS 2.02-21.99 g/L, TSS 0.62-2.76 g/L, transparency 4.5-14 cm, precipitation 64-1992 mm, NO2-N 1.94-2.58 µg/L, PO4-P 0.45-1.84 µg/L, SiO3-Si 130.46-956.31 µg/L during investigation period. Average values of physicochemical parameters were found to be in compliance with standard guidelines. The ship breaking activities near experimental location possess negative impacts on local geomorphology, freshwater inputs, precipitation and aquatic environment as well. Moreover, wind driven forces, tidal action, wave characteristics and changes in monsoon pattern regulate the coastal processes. This research suggests the importance of regular monitoring to assess present status of water quality and future prospect of aquaculture in the Chittagong coastal zone.

Application progress of solid 29Si, 27Al NMR in the research of cement-based materials

International Nuclear Information System (INIS)

Feng Chunhua; Wang Xijian; Li Dongxu

2014-01-01

Background: The solid-state Nuclear Magnetic Resonance (NMR) is an effective method for the research of cement-based materials. Now it focuses on using solid 29 Si and 27 Al NMR to research the hydration structure of the cement-based materials in cement chemistry. Purpose: A theoretical guidance is proposed for solid 29 Si and 27 Al NMR technology used in cement chemistry research. Methods: We reviewed the application of solid 29 Si and 27 Al NMR in the cement-based materials and analyzed the problem among the researches. Results: This paper introduced an fundamental, relevant-conditions and basic parameters of NMR, and studied the technical parameters of solid 29 Si and 27 Ai NMR together with the relationship among the hydration structure of cement based material. Moreover, this paper reviewed the related domestic and overseas achievements in the research of hydration structure of the cement-based materials using solid 29 Si and 27 Al NMR. Conclusion: There were some problems in the research on cement-based materials by technology of solid 29 Si and 27 Al NMR. NMR will promote the Hydration theory of cement-based material greatly. (authors)

Airborne Mission Concept for Coastal Ocean Color and Ecosystems Research

Science.gov (United States)

Guild, Liane S.; Hooker, Stanford B.; Morrow, John H.; Kudela, Raphael M.; Palacios, Sherry L.; Torres Perez, Juan L.; Hayashi, Kendra; Dunagan, Stephen E.

2016-01-01

NASA airborne missions in 2011 and 2013 over Monterey Bay, CA, demonstrated novel above- and in-water calibration and validation measurements supporting a combined airborne sensor approach (imaging spectrometer, microradiometers, and a sun photometer). The resultant airborne data characterize contemporaneous coastal atmospheric and aquatic properties plus sea-truth observations from state-of-the-art instrument systems spanning a next-generation spectral domain (320-875 nm). This airborne instrument suite for calibration, validation, and research flew at the lowest safe altitude (ca. 100 ft or 30 m) as well as higher altitudes (e.g., 6,000 ft or 1,800 m) above the sea surface covering a larger area in a single synoptic sortie than ship-based measurements at a few stations during the same sampling period. Data collection of coincident atmospheric and aquatic properties near the sea surface and at altitude allows the input of relevant variables into atmospheric correction schemes to improve the output of corrected imaging spectrometer data. Specific channels support legacy and next-generation satellite capabilities, and flights are planned to within 30 min of satellite overpass. This concept supports calibration and validation activities of ocean color phenomena (e.g., river plumes, algal blooms) and studies of water quality and coastal ecosystems. The 2011 COAST mission flew at 100 and 6,000 ft on a Twin Otter platform with flight plans accommodating the competing requirements of the sensor suite, which included the Coastal-Airborne In-situ Radiometers (C-AIR) for the first time. C-AIR (Biospherical Instruments Inc.) also flew in the 2013 OCEANIA mission at 100 and 1,000 ft on the Twin Otter below the California airborne simulation of the proposed NASA HyspIRI satellite system comprised of an imaging spectrometer and thermal infrared multispectral imager on the ER-2 at 65,000 ft (20,000 m). For both missions, the Compact-Optical Profiling System (Biospherical

Coastal ecosystems, productivity and ecosystem protection: Coastal ecosystem management

International Nuclear Information System (INIS)

Ngoile, M.A.K.; Horrill, C.J.

1993-01-01

The coastal zone is a complex ecosystem under the influence of physical, chemical and biological processes. Under natural conditions these processes interact and maintain an equilibrium in the coastal ecosystem. Man makes a variety of important uses of coastal resources, ranging from harvesting of living resources, extraction of nonliving resources, and recreation, to the disposal of wastes. Man's extensive use of the oceans introduces factors which bring about an imbalance in the natural processes, and may result in harmful and hazardous effects to life hindering further use. Man's pressure on the resources of the coastal zone is already manifest and will increase manifold. This calls for an immediate solution to the protection and sustainable use of coastal resources. The current sectorized approach to the management of human activities will not solve the problem because the different resources of the coastal zone interact in such a manner that disturbances in one cause imbalance in the others. This is further complicated by the sectorized approach to research and limited communication between policy makers, managers, and scientists. This paper discusses strategies for managing coastal-resources use through an integrated approach. The coastal zone is presented as a unified ecosystem in equilibrium and shows that man's extensive use of the coastal resources destabilizes this equilibrium. Examples from the East Africa Region are presented. 15 refs, 2 figs, 3 tabs

Management Restoration Plans for Coastal Villages

Directory of Open Access Journals (Sweden)

Rudianto Rudianto

2017-03-01

Full Text Available The village is located in the coastal area up to this time has decreased the quality of the coastal environment either caused by the process of natural or anthropogenic processes. Coastal damage Persistent will affect people's lives. Based on studies conducted by Rudianto (2013 and continued research by Rudianto (2014 on the institutional model for implementing the strategy, the resulting output coast of research called restoration plan for coastal villages or R2DP coastal villages. The objective of R2DP is helping the village administration to alleviate the problems of coastal areas. R2DP is a guideline that will be used by the village government based on a legal framework called the village regulations. The method used to compile R2DP is descriptive method. By using the method of Miles and Huberman (1984 used data reduction techniques. This technique is to pick and choose which data is critical to focus on the purpose of research. the results of research to produce findings about the restoration plan or a coastal village called R2DP. The essence of the mechanism and procedure R2DP is doing the restoration work by using institutions as a means of restoration.

Need Analysis of Coastal Fisherman empowerment Based on Economics education and Potential Coastal in Minahasa Regency of North Sulawesi

Science.gov (United States)

Wantah, Edwin; Djatmika, Ery Tri; Witjaksono, Mit; Wahyono, Hari

2018-05-01

This research article aims to describe the need analysis process of coastal fisherman empowerment in North Minahasa Regency of North Sulawesi Province through internalization of economics education and technical training based on potential coastal.This research used descriptive qualitative research design by using survey, field observational interview and Focus Group Discussion (FGD) method. The research subjects were 40 coastal fishermen in North Minahasa Regency spread in two sub-districts, namely Wori Sub-district and Kema Sub-district in North Minahasa Regency, who have capture capacity of 10 gross ton sand below. The results of needs analysis were identified in observation, in-depth interview, and Focus Group Discussion (FGD), which was confirmed by the survey results indicating that 87.5% of the coastal fishermen need knowledge and understanding of characteristics, attitudes and principles to become successful entrepreneurs, which can be implemented in productive business activities on coastal area, while 92.5% of the coastal fishermen require an understanding of creativity and innovation and its implementation, 90% of the coastal fishermen require knowledge of business diversification based on coastal area and marine potentials, 90% of the fishermen stated that they need knowledge and understanding of the process of processed fish products because of the abundant raw materials, 80% of the coastal fishermen said that they need an understanding of the way to establish business partnerships and business networks with other business groups, 90% of the coastal fishermen stated that they need an understanding of the way to form fishermen joint business groups and the way to develop the business group. 92.5% of the coastal fishermen need an understanding of business capital and the way to access business capital, and 85% of the coastal fishermen said that they need to understand money management, the way to plan proper financial allocations, and saving procedures

Risk Analysis of Coastal hazard Considering Sea-level Rise and Local Environment in Coastal Area

Science.gov (United States)

Sangjin, P.; Lee, D. K.; KIM, H.; Ryu, J. E.; Yoo, S.; Ryoo, H.

2014-12-01

Recently, natural hazards has been more unpredictable with increasing frequency and strength due to climate change. Especially, coastal areas would be more vulnerable in the future because of sea-level rise (SLR). In case of Korea, it is surrounded by oceans and has many big cities at coastal area, thus a hazard prevention plan in coastal area is absolutely necessary. However, prior to making the plan, finding areas at risk would be the first step. In order to find the vulnerable area, local characteristics of coastal areas should also be considered along with SLR. Therefore, the objective of the research is to find vulnerable areas, which could be damaged by coastal hazards considering local environment and SLR of coastal areas. Spatial scope of the research was set up as 1km from the coastline according to the 'coastal management law' in Korea. The assessment was done up to the year of 2050, and the highest sea level rise scenario was used. For risk analysis, biophysical and socioeconomic characteristics were considered as to represent local characteristics of coastal area. Risk analysis was carried out through the combination of 'possibility of hazard' and the 'level of damages', and both of them reflect the above-mentioned regional characteristics. Since the range of inundation was narrowed down to the inundation from typhoon in this research, the possibility of inundation caused by typhoon was estimated by using numerical model, which calculated the height of storm surge considering wave, tide, sea-level pressure and SLR. Also the level of damage was estimated by categorizing the socioeconomic character into four factors; human, infrastructure, ecology and socioeconomic. Variables that represent each factor were selected and used in damage estimation with their classification and weighting value. The result shows that the urban coastal areas are more vulnerable and hazardous than other areas because of socioeconomic factors. The east and the south coast are

Research on the hydrogeological and geochemical conditions at the coastal area and submarine formations

International Nuclear Information System (INIS)

Tokunaga, Tomochika; Taniguchi, Makoto; Goto, Junji

2003-05-01

One of the major concerns for the high-level radioactive waste disposal is the possibility of the radionuclides to reach biosphere by groundwater flow. Recent research results have shown that the fresh groundwater discharge from subsea formations are widespread phenomena, thus, it is necessary to evaluate the submarine groundwater discharge as possible pathways of contaminant discharge towards the biosphere. It is also important to unravel the groundwater flow and associated material transport at the coastal area and subsea formations. To better understand the groundwater flow processes and the submarine groundwater discharge, we have conducted the hydrological, hydrogeological, geochemical, and numerical modeling studies at the Kurobe alluvial fan and its offshore, Toyama Prefecture, Japan. In this report, the results of the following research activities are presented: 1) Development and application of a method to detect the locations of the submarine groundwater discharge. 2) Development and application of a method to collect uncontaminated groundwater samples from subsea formations. 3) Measurements of submarine groundwater discharge fluxes by automated seepage meter. 4) Hydrological and geochemical studies for groundwater flow at the coastal area. 5) Geochemical studies to understand sources of fresh submarine groundwater discharge. 6) Examination of groundwater flow and submarine groundwater discharge using methane concentration and carbon isotope ratio. 7) Numerical modeling studies for coastal groundwater flow system. (author)

Proceedings of a workshop on coastal impacts and adaptation related to climate change : the C-CIARN Coastal Node

International Nuclear Information System (INIS)

2001-03-01

Coastal zones are sensitive to increases in air, sea and ground temperatures as well as to variations in sea level, precipitation, ice thickness, and storm intensity. In order to address concerns regarding climate change in coastal areas, the government of Canada established a Coastal Node as part of the Canadian Climate Impact and Adaptation Research Network (C-CIARN). The role of C-CIARN Coastal Node was recently outlined in a workshop aimed at providing guidelines and research priorities for stakeholders from all coastal regions of Canada. The workshop considered the integration of the node function with one or more of the regional nodes or with the fisheries node. Topics of discussion included both direct impacts on coastal infrastructure or human-use activities as well as indirect impacts resulting from changes in the ecosystem. refs., tabs

Areas of research and manpower development for coastal zone management

Digital Repository Service at National Institute of Oceanography (India)

Sumitra-Vijayaraghavan

stream_size 6 stream_content_type text/plain stream_name Trg_Course_Coastal_Zone_Mgmt_1993_74.pdf.txt stream_source_info Trg_Course_Coastal_Zone_Mgmt_1993_74.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset...

Joining of SiC ceramics and SiC/SiC composites

Energy Technology Data Exchange (ETDEWEB)

Rabin, B.H. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

1996-08-01

This project has successfully developed a practical and reliable method for fabricating SiC ceramic-ceramic joints. This joining method will permit the use of SiC-based ceramics in a variety of elevated temperature fossil energy applications. The technique is based on a reaction bonding approach that provides joint interlayers compatible with SiC, and excellent joint mechanical properties at temperatures exceeding 1000{degrees}C. Recent emphasis has been given to technology transfer activities, and several collaborative research efforts are in progress. Investigations are focusing on applying the joining method to sintered {alpha}-SiC and fiber-reinforced SiC/SiC composites for use in applications such as heat exchangers, radiant burners and gas turbine components.

Summary of wildlife-related research on the coastal plain of the Arctic National Wildlife Refuge, Alaska, 2002–17

Science.gov (United States)

Pearce, John M.; Flint, Paul L.; Atwood, Todd C.; Douglas, David C.; Adams, Layne G.; Johnson, Heather E.; Arthur, Stephen M.; Latty, Christopher J.

2018-01-23

We summarize recent (2002–17) publicly available information from studies within the 1002 Area of the Arctic National Wildlife Refuge as well as terrestrial and coastal ecosystems elsewhere on the Arctic Coastal Plain that are relevant to the 1002 Area. This report provides an update on earlier research summaries on caribou (Rangifer tarandus), forage quality and quantity, polar bears (Ursus maritimus), muskoxen (Ovibos moschatus), and snow geese (Chen caerulescens). We also provide information on new research related to climate, migratory birds, permafrost, coastal erosion, coastal lagoons, fish, water resources, and potential effects of industrial disturbance on wildlife. From this literature review, we noted evidence for change in the status of some wildlife and their habitats, and the lack of change for others. In the 1002 Area, muskox numbers have decreased and the Porcupine Caribou Herd has exhibited variation in use of the area during the calving season. Polar bears are now more common on shore in summer and fall because of declines in sea ice in the Beaufort Sea. In a study spanning 25 years, there were no significant changes in vegetation quality and quantity, soil conditions, or permafrost thaw in the coastal plain of the 1002 Area. Based on studies from the central Arctic Coastal Plain, there are persistent and emerging uncertainties about the long-term effects of energy development for caribou. In contrast, recent studies that examined direct and indirect effects of industrial activities and infrastructure on birds in the central Arctic Coastal Plain found little effect for the species and disturbances examined, except for the possibility of increased predator activity near human developments.

Nanocrystalline Si pathway induced unipolar resistive switching behavior from annealed Si-rich SiNx/SiNy multilayers

International Nuclear Information System (INIS)

Jiang, Xiaofan; Ma, Zhongyuan; Yang, Huafeng; Yu, Jie; Wang, Wen; Zhang, Wenping; Li, Wei; Xu, Jun; Xu, Ling; Chen, Kunji; Huang, Xinfan; Feng, Duan

2014-01-01

Adding a resistive switching functionality to a silicon microelectronic chip is a new challenge in materials research. Here, we demonstrate that unipolar and electrode-independent resistive switching effects can be realized in the annealed Si-rich SiN x /SiN y multilayers with high on/off ratio of 10 9 . High resolution transmission electron microscopy reveals that for the high resistance state broken pathways composed of discrete nanocrystalline silicon (nc-Si) exist in the Si nitride multilayers. While for the low resistance state the discrete nc-Si regions is connected, forming continuous nc-Si pathways. Based on the analysis of the temperature dependent I-V characteristics and HRTEM photos, we found that the break-and-bridge evolution of nc-Si pathway is the origin of resistive switching memory behavior. Our findings provide insights into the mechanism of the resistive switching behavior in nc-Si films, opening a way for it to be utilized as a material in Si-based memories.

Nanocrystalline Si pathway induced unipolar resistive switching behavior from annealed Si-rich SiNx/SiNy multilayers

Science.gov (United States)

Jiang, Xiaofan; Ma, Zhongyuan; Yang, Huafeng; Yu, Jie; Wang, Wen; Zhang, Wenping; Li, Wei; Xu, Jun; Xu, Ling; Chen, Kunji; Huang, Xinfan; Feng, Duan

2014-09-01

Adding a resistive switching functionality to a silicon microelectronic chip is a new challenge in materials research. Here, we demonstrate that unipolar and electrode-independent resistive switching effects can be realized in the annealed Si-rich SiNx/SiNy multilayers with high on/off ratio of 109. High resolution transmission electron microscopy reveals that for the high resistance state broken pathways composed of discrete nanocrystalline silicon (nc-Si) exist in the Si nitride multilayers. While for the low resistance state the discrete nc-Si regions is connected, forming continuous nc-Si pathways. Based on the analysis of the temperature dependent I-V characteristics and HRTEM photos, we found that the break-and-bridge evolution of nc-Si pathway is the origin of resistive switching memory behavior. Our findings provide insights into the mechanism of the resistive switching behavior in nc-Si films, opening a way for it to be utilized as a material in Si-based memories.

Maintaining a way of life for São Miguel Island (the Azores archipelago, Portugal): an assessment of coastal processes and protection.

Science.gov (United States)

Ng, K; Phillips, M R; Borges, P; Thomas, T; August, P; Calado, H; Veloso-Gomes, F

2014-05-15

Traditional hard engineering structures and recently emerging soft engineering alternatives have been employed to protect vulnerable coastlines. Despite negative publicity, they have ensured community survival where socio-economic benefits outweigh adverse impacts. This is especially true for Small Islands (SI) where increasing sea levels and storm intensities threaten already limited land availability. This paper presents coastal vulnerability in São Miguel Island (the Azores SI archipelago) and considers SI issues with regard to coastal land loss. Regional wave statistics using 1998 to 2011 wind record showed: periods ranging from 7 to 13s (circa 83%); wave heights between 1 and 3m (circa 60%); and increasing trends in westerly (p=0.473), easterly (p=0.632) and southeasterly (p=0.932) waves. Sea level analyses between 1978 and 2007 indicated a statistically significant rising trend (2.5 ± 0.4 mm yr(-1); p=0.000), while between 1996 and 2007 it was 3.3 ± 1.5 mm yr(-1) (p=0.025), agreeing with other global sea level studies. Based on 2001 and 2008 population data and using zonal statistics, circa 60% of the Island's population was found to reside within 1 km of the sea and the percentage of total population was linearly correlated with distance from the shoreline (r(2)=99%). Three case studies show hard coastal engineering solutions preserved Azorean coastal lifestyle and had little or no observed negative impacts on their environs. Although hard engineering is likely to remain a valuable and feasible coastal protection option, an inventory of São Miguel's population distribution, surf breaks, bathymetry and coastal erosion rates showed the potential of using multifunctional artificial reefs as a soft engineering solution. These offshore submerged breakwaters offer coastal protection while providing additional benefits such as surfing amenity and beach widening. Consequently, findings of this work can inform other SI communities. Copyright © 2014 Elsevier B

Environmental literacy in agriculture and coastal areas

Science.gov (United States)

Pujianti, N.; Munandar, A.; Surakusumah, W.

2018-05-01

This research aim to investigate the environmental literacy of junior high school students in agricultural and coastal areas in Subang based on knowledge, cognitive skill and attitudes toward to environment. This research used descriptive method. The subjects of the research were 7 grade students of junior high school and involved 62 participants in agriculture area and 64 participants in coastal area. The instrument of environment literacy adapted from Middle School Environment Literacy Survey (MSELS) and adapted to the context of agricultural and coastal area. The results showed that: environmental literacy in agricultural areas is 169.30 with moderate category and environmental literacy in the coastal area is 152.61 in the moderate category.

Research on SiC Whisker Prepared by H-PSO

Directory of Open Access Journals (Sweden)

WANG Yao

2017-10-01

Full Text Available SiC whiskers were prepared on the matrix of graphite by using high hydrogenous silicone oil(PSO as raw material. The effect of surface conditions of graphite and heating temperature on the growth of SiC whisker was mainly studied in this paper. The main factor which affects the nucleation and growth of SiC whisker is the heating temperature, with the heating temperature rising, the production of SiC whisker increases. The surface condition of graphite matrix also influences the growth of SiC whisker. With the nucleation points provided by graphite matrix defects increasing, the production of SiC whisker incleases and SiC whisker starts to overlap with each other. The formation process of SiC whisker includes two steps:nucleation and growth. SiC whisker nucleates at low temperature and grows at high temperature, which follows the VLS (vapor-liquid-solid growth mechanism.

The Coastal Ocean Prediction Systems program: Understanding and managing our coastal ocean. Volume 2: Overview and invited papers

Energy Technology Data Exchange (ETDEWEB)

1990-05-15

This document is a compilation of summaries of papers presented at the Coastal Ocean Prediction Systems workshop. Topics include; marine forecasting, regulatory agencies and regulations, research and application models, research and operational observing, oceanic and atmospheric data assimilation, and coastal physical processes.

Decision Support Model for Optimal Management of Coastal Gate

Science.gov (United States)

Ditthakit, Pakorn; Chittaladakorn, Suwatana

2010-05-01

The coastal areas are intensely settled by human beings owing to their fertility of natural resources. However, at present those areas are facing with water scarcity problems: inadequate water and poor water quality as a result of saltwater intrusion and inappropriate land-use management. To solve these problems, several measures have been exploited. The coastal gate construction is a structural measure widely performed in several countries. This manner requires the plan for suitably operating coastal gates. Coastal gate operation is a complicated task and usually concerns with the management of multiple purposes, which are generally conflicted one another. This paper delineates the methodology and used theories for developing decision support modeling for coastal gate operation scheduling. The developed model was based on coupling simulation and optimization model. The weighting optimization technique based on Differential Evolution (DE) was selected herein for solving multiple objective problems. The hydrodynamic and water quality models were repeatedly invoked during searching the optimal gate operations. In addition, two forecasting models:- Auto Regressive model (AR model) and Harmonic Analysis model (HA model) were applied for forecasting water levels and tide levels, respectively. To demonstrate the applicability of the developed model, it was applied to plan the operations for hypothetical system of Pak Phanang coastal gate system, located in Nakhon Si Thammarat province, southern part of Thailand. It was found that the proposed model could satisfyingly assist decision-makers for operating coastal gates under various environmental, ecological and hydraulic conditions.

Particle Tracking Model (PTM) with Coastal Modeling System (CMS)

Science.gov (United States)

2015-11-04

Coastal Inlets Research Program Particle Tracking Model (PTM) with Coastal Modeling System ( CMS ) The Particle Tracking Model (PTM) is a Lagrangian...currents and waves. The Coastal Inlets Research Program (CIRP) supports the PTM with the Coastal Modeling System ( CMS ), which provides coupled wave...and current forcing for PTM simulations. CMS -PTM is implemented in the Surface-water Modeling System, a GUI environment for input development

Across Hydrological Interfaces from Coastal Watersheds to the Open Lake: Finding Landscape Signals in the Great Lakes Coastal Zone

Science.gov (United States)

Over the past decade, our group has been working to bring coastal ecosystems into integrated basin-lakewide monitoring and assessment strategies for the Great Lakes. We have conducted a wide range of research on coastal tributaries, coastal wetlands, semi-enclosed embayments an...

The Coastal Ocean Prediction Systems program: Understanding and managing our coastal ocean

International Nuclear Information System (INIS)

1990-01-01

The proposed COPS (Coastal Ocean Prediction Systems) program is concerned with combining numerical models with observations (through data assimilation) to improve our predictive knowledge of the coastal ocean. It is oriented toward applied research and development and depends upon the continued pursuit of basic research in programs like COOP (Coastal Ocean Processes); i.e., to a significant degree it is involved with ''technology transfer'' from basic knowledge to operational and management applications. This predictive knowledge is intended to address a variety of societal problems: (1) ship routing, (2) trajectories for search and rescue operations, (3) oil spill trajectory simulations, (4) pollution assessments, (5) fisheries management guidance, (6) simulation of the coastal ocean's response to climate variability, (7) calculation of sediment transport, (8) calculation of forces on structures, and so forth. The initial concern is with physical models and observations in order to provide a capability for the estimation of physical forces and transports in the coastal ocean. For all these applications, there are common needs for physical field estimates: waves, tides, currents, temperature, and salinity, including mixed layers, thermoclines, fronts, jets, etc. However, the intent is to work with biologists, chemists, and geologists in developing integrated multidisciplinary prediction systems as it becomes feasible to do so. From another perspective, by combining observations with models through data assimilation, a modern approach to monitoring is provided through whole-field estimation

Hyperspectral Imager for the Coastal Ocean (HICO): Overview, Operational Updates, and Coastal Ocean Applications

Science.gov (United States)

Davis, Curtiss O.; Kappus, Mary E.; Bowles, Jeffrey H.; Evans, Cynthia A.; Stefanov, William L.

2014-01-01

The Hyperspectral Imager for the Coastal Ocean (HICO) was built to measure in-water properties of complex coastal regions. HICO enables synoptic coverage; 100-meter spatial resolution for sampling the variability and spatial irregularity of coastal waters; and high spectral resolution to untangle the signals from chlorophyll, colored dissolved organic matter, suspended sediments and varying bottom types. HICO was built by the Naval Research Laboratory, installed on the International Space Station (ISS) in September 2009, and operated for ONR for the first three years. In 2013, NASA assumed sponsorship of operations in order to leverage HICO's ability to address their Earth monitoring mission. This has opened up access of HICO data to the broad research community. Over 8000 images are now available on NASA's Ocean Color Website (http://oceancolor.gsfc.nasa.gov/cgi/browse.pl?sen=hi). Oregon State University's HICO website (http://hico.coas.oregonstate.edu) remains the portal for researchers to request new collections and access their requested data. We will present updates on HICO's calibration and improvements in geolocation and show examples of the use of HICO data to address issues in the coastal ocean and Great Lakes.

C2R2: Training Students To Build Coastal Resilience

Science.gov (United States)

Ferraro, C.; Kopp, R. E.; Jordan, R.; Gong, J.; Andrews, C.; Auermuller, L. M.; Herb, J.; McDonnell, J. D.; Bond, S.

2017-12-01

In the United States, about 23 million people live within 6 meters of sea level. In many parts of the country, sea-level rise between 1960 and 2010 has already led to a 2-5-fold increase in the rate of `nuisance' flooding. On top of rising seas, intensifying hurricanes and more frequent extremes of heat, humidity and precipitation pose additional risks to coastal societies, economies and ecosystems. Addressing risks posed by changing climate conditions in coastal areas demands innovative strategies that intersect multiple disciplines including engineering, ecology, communication, climate science, and community planning. To be usable, it also requires engaging coastal stakeholders in the development of research questions, the assessment of implications of research for planning and policy, and the communication of research results. Yet traditional, disciplinary programs are poorly configured to train the workforce needed to assess coastal climate risk and to develop and deploy integrated strategies for increasing coastal climate resilience. Coastal Climate Risk & Resilience (C2R2) is an NSF Research Traineeship (NRT) working to prepare the workforce that will build coastal resilience in the face of climate risks. Through its trainee and certificate programs, C2R2 works with graduate students at Rutgers University from multiple disciplines to better integrate all the elements of coastal systems and to communicate effectively with coastal stakeholders. C2R2 students will acquire the knowledge and practical skills needed to become leading researchers and practitioners tackling the critical challenges of coastal resilience.

Analysis of Stakeholder-Defined Needs in Northeast U.S. Coastal Communities to Determine Gaps in Research Informing Coastal Resilience Planning

Science.gov (United States)

Molino, G. D.; Kenney, M. A.; Sutton-Grier, A.; Penn, K.

2017-12-01

The impacts of climate change on our coastlines are increasing pressure on communities, ecosystems, infrastructure, and state-to-local economies in the northeastern United States (U.S.). As a result of current or imminent risk of acute and chronic hazards, local, state and regional entities have taken steps to identify and address vulnerabilities to climate change. Decisions to increase coastal infrastructure resilience and grey, green, and cultural infrastructure solutions requires physical, natural, and social science that is useful for decision-making and effective science translation mechanisms. Despite the desire to conduct or fund science that meets the needs of communities, there has been no comprehensive analysis to determine stakeholder-defined research needs. To address this gap, this study conducts a stakeholder needs analysis in northeast U.S. coastal communities to determine gaps in information and translation processes supporting coastal resilience planning. Documents were sourced from local, state, and regional organizations in both the public and private sectors, using the northeast region defined by the third National Climate Assessment. Modeled after Dilling et al. (2015), a deductive coding schema was developed that categorized documents using specific search terms such as "Location and condition of infrastructure" and "Proactive planning". A qualitative document analysis was then executed using NVivo to formally identify patterns and themes present in stakeholder surveys, workshop proceedings, and reports. Initial stakeholder priorities centered around incorporation of climate science into planning and decision making regarding vulnerabilities of infrastructure, enhanced emergency planning and response, and communication of key information.

75 FR 28593 - Board on Coastal Engineering Research

Science.gov (United States)

2010-05-21

...-Level Changes along the U.S. Atlantic Coast, Atlantic Region Coastal Storms, Overview of Climatic Variation Effects on Extratropical and Tropical Storms, Evidence for a Changing North Pacific Wave Climate...

Ecological Effects of Sea Level Rise: Advancing coastal management through integrated research and engagement

Science.gov (United States)

Kidwell, D. M.

2012-12-01

attention has been given to forecast and sea level rise prediction timelines and rates and methods for delivering tools and products to stakeholders and managers. Targeted manager focus groups are also being used to provide additional guidance to the science team. This presentation will provide an overview of the project with particular attention to the lessons learned through the implementation of this large-scale research project and engagement with the coastal management community.

NASA COAST and OCEANIA Airborne Missions Support Ecosystem and Water Quality Research in the Coastal Zone

Science.gov (United States)

Guild, Liane; Kudela, Raphael; Hooker, Stanford; Morrow, John; Russell, Philip; Palacios, Sherry; Livingston, John M.; Negrey, Kendra; Torres-Perez, Juan; Broughton, Jennifer

2014-01-01

phytoplankton for coastal zone research.

Nanocrystalline Si pathway induced unipolar resistive switching behavior from annealed Si-rich SiN{sub x}/SiN{sub y} multilayers

Energy Technology Data Exchange (ETDEWEB)

Jiang, Xiaofan; Ma, Zhongyuan, E-mail: zyma@nju.edu.cn; Yang, Huafeng; Yu, Jie; Wang, Wen; Zhang, Wenping; Li, Wei; Xu, Jun; Xu, Ling; Chen, Kunji; Huang, Xinfan; Feng, Duan [National Laboratory of Solid State Microstructures, Jiangsu Provincial Key Laboratory of Photonic Electronic Materials Sciences and Technology, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093 (China)

2014-09-28

Adding a resistive switching functionality to a silicon microelectronic chip is a new challenge in materials research. Here, we demonstrate that unipolar and electrode-independent resistive switching effects can be realized in the annealed Si-rich SiN{sub x}/SiN{sub y} multilayers with high on/off ratio of 10{sup 9}. High resolution transmission electron microscopy reveals that for the high resistance state broken pathways composed of discrete nanocrystalline silicon (nc-Si) exist in the Si nitride multilayers. While for the low resistance state the discrete nc-Si regions is connected, forming continuous nc-Si pathways. Based on the analysis of the temperature dependent I-V characteristics and HRTEM photos, we found that the break-and-bridge evolution of nc-Si pathway is the origin of resistive switching memory behavior. Our findings provide insights into the mechanism of the resistive switching behavior in nc-Si films, opening a way for it to be utilized as a material in Si-based memories.

Global challenges in integrated coastal zone management

DEFF Research Database (Denmark)

integration of data and information in policy and management, combining expertise from nature and social science, to reach a balanced and sustainable development of the coastal zone. This important book comprises the proceedings of The International Symposium on Integrated Coastal Zone Management, which took....../mitigation to change in coastal systems Coastal governance Linking science and management Comprising a huge wealth of information, this timely and well-edited volume is essential reading for all those involved in coastal zone management around the globe. All libraries in research establishments and universities where...

Predicting impact of SLR on coastal flooding in Banda Aceh coastal defences

Science.gov (United States)

Al'ala, Musa; Syamsidik, Kato, Shigeru

2017-10-01

Banda Aceh is a low-lying city located at the northern tip of Sumatra Island and situated at the conjuncture of Malacca Strait and the Andaman Sea. A Sea Level Rise (SLR) rate at 7 mm/year has been observed around this region. In the next 50 years, this city will face a serious challenge to encounter impacts of the sea level rise, such as frequent coastal floodings. This study is aimed at estimating impacts of the sea level rise induced coastal floodings on several types of coastal structures and city drainage system. Numerical simulations of Delft3D were applied to investigate the influence of the gradual sea level rise in 50 years. The hydrodynamic process of coastal flooding and sediment transport were simulated by Delft3D-Flow. Topography and bathymetry data were collected from GEBCO and updated with the available nautical chart (DISHIDROS, JICA, and field measurements). Hydrodynamic process gains the flow process revealing the level of the sea water intrusion also observed in the model. Main rivers (Krueng Aceh, Krueng Neng, and Alue Naga Flood Canal) and the drainage system were observed to see the tides effects on coastal structures and drainage system. The impact on coastal community focusing on affected area, shoreline retreat, the rate of sea intrusion was analyzed with spatial tools. New coastal line, coastal flooding vulnerable area, and the community susceptibility properties map influenced by 50 years sea level rise is produced. This research found that the city needs to address strategies to anticipate the exacerbating impacts of the sea level rise by managing its coastal spatial planning and modify its drainage system, especially at the drainage outlets.

Circumferential tensile test method for mechanical property evaluation of SiC/SiC tube

Energy Technology Data Exchange (ETDEWEB)

Yu, Ju-Hyeon, E-mail: 15096018@mmm.muroran-it.ac.jp [Graduate School, Muroran Institute of Technology, 27-1, Muroran, Hokkaido (Japan); Kishimoto, Hirotatsu [Graduate School, Muroran Institute of Technology, 27-1, Muroran, Hokkaido (Japan); OASIS, Muroran Institute of Technology, 27-1, Muroran, Hokkaido (Japan); Park, Joon-soo [OASIS, Muroran Institute of Technology, 27-1, Muroran, Hokkaido (Japan); Nakazato, Naofumi [Graduate School, Muroran Institute of Technology, 27-1, Muroran, Hokkaido (Japan); Kohyama, Akira [OASIS, Muroran Institute of Technology, 27-1, Muroran, Hokkaido (Japan)

2016-11-01

Highlights: • NITE SiC/SiC cooling channel system to be a candidate of divertor system in future. • Hoop strength is one of the important factors for a tube. • This research studies the relationship between deformation and strain of SiC/SiC tube. - Abstract: SiC fiber reinforced/SiC matrix (SiC/SiC) composite is expected to be a candidate material for the first-wall, components in the blanket and divertor of fusion reactors in future. In such components, SiC/SiC composites need to be formed to be various shapes. SiC/SiC tubes has been expected to be employed for blanket and divertor after DEMO reactor, but there is not established mechanical investigation technique. Recent progress of SiC/SiC processing techniques is likely to realize strong, having gas tightness SiC/SiC tubes which will contribute for the development of fusion reactors. This research studies the relationship between deformation and strain of SiC/SiC tube using a circumferential tensile test method to establish a mechanical property investigation method of SiC/SiC tubes.

Coastal Morphology and Coastal Protection

NARCIS (Netherlands)

Van de Graaff, J.

2009-01-01

Lecture notes ct5309. Tides, currents and water; coastal problems; sediment transport processes; coastal transport modes; longshore transport; cross-shore transport; fundamentals of mud; channels and trenches; coastal protection; application of structures; application of nourishments.

Coastal zone

International Nuclear Information System (INIS)

2002-01-01

The report entitled Climate Change Impacts and Adaptation : A Canadian Perspective, presents a summary of research regarding the impacts of climate change on key sectors over the past five years as it relates to Canada. This chapter on the coastal zone focuses on the impact of climate change on Canada's marine and Great Lakes coasts with tips on how to deal with the impacts associated with climate change in sensitive environments. This report is aimed at the sectors that will be most affected by adaptation decisions in the coastal zone, including fisheries, tourism, transportation and water resources. The impact of climate change in the coastal zone may include changes in water levels, wave patterns, storm surges, and thickness of seasonal ice cover. The Intergovernmental Panel on Climate Change projects global average sea level will rise between 9 and 88 centimetres between 1990 to 2100, but not all areas of Canada will experience the same rate of future sea level change. The main physical impact would be shoreline change that could result in a range of biophysical and socio-economic impacts, some beneficial, some negative. The report focuses on issues related to infrastructure and communities in coastal regions. It is noted that appropriate human adaptation will play a vital role in reducing the extent of potential impacts by decreasing the vulnerability of average zone to climate change. The 3 main trends in coastal adaptation include: (1) increase in soft protection, retreat and accommodation, (2) reliance on technology such as geographic information systems to manage information, and (3) awareness of the need for coastal adaptation that is appropriate for local conditions. 61 refs., 7 figs

Status and prospects for SiC-SiC composite materials development for fusion applications

International Nuclear Information System (INIS)

Sharafat, S.; Jones, R.H.; Kohyama, A.; Fenici, P.

1995-01-01

Silicon carbide (SiC) composites are very attractive for fusion applications because of their low afterheat and low activation characteristics coupled with excellent high temperature properties. These composites are relatively new materials that will require material development as well as evaluation of hermiticity, thermal conductivity, radiation stability, high temperature strength, fatigue, thermal shock, and joining techniques. The radiation stability of SiC-SiC composites is a critical aspect of their application as fusion components and recent results will be reported. Many of the non-fusion specific issues are under evaluation by other ceramic composite development programs, such as the US national continuous fiber ceramic composites.The current development status of various SiC-SiC composites research and development efforts is given. Effect of neutron irradiation on the properties of SiC-SiC composite between 500 and 1200 C are reported. Novel high temperature properties specific to ceramic matrix composite (CMC) materials are discussed. The chemical stability of SiC is reviewed briefly. Ongoing research and development efforts for joining CMC materials including SiC-SiC composites are described. In conclusion, ongoing research and development efforts show extremely promising properties and behavior for SiC-SiC composites for fusion applications. (orig.)

Atomization of U3Si2/U3Si for research reactor fuel

International Nuclear Information System (INIS)

Kuk, Il Hiun

2004-01-01

Instead of comminuting, U 3 Si 2 /U 3 Si powders are produced by atomizating directly from the molten alloys. Many benefits are introduced by applying the atomization technique: reduction of the process, homogeneous alloy composition within a particle and between particles, increase of the thermal conductivity and decrease of the chemical reactivity with aluminium due to particle's spherical shape. (author)

2011 Summary: Coastal wetland restoration research

Science.gov (United States)

Kowalski, Kurt P.; Wiley, Michael J.; Wilcox, Douglas A.; Carlson Mazur, Martha L.; Czayka, Alex; Dominguez, Andrea; Doty, Susan; Eggleston, Mike; Green, Sean; Sweetman, Amanda

2014-01-01

The Great Lakes Restoration Initiative (GLRI) projects currently taking place in Great Lakes coastal wetlands provide a unique opportunity to study ecosystem response to management actions as practitioners strive to improve wetland function and increase ecosystem services. Through a partnership between the U.S. Geological Survey – Great Lakes Science Center (GLSC), U.S. Fish and Wildlife Service (USFWS), and Ducks Unlimited, a GLRI-funded project has reestablished the hydrologic connection between an intensively managed impounded wetland (Pool 2B) and Crane Creek, a small Lake Erie tributary, by building a water-control structure that was opened in the spring of 2011. The study site is located within the USFWS Ottawa National Wildlife Refuge (ONWR) and lies within the boundaries of the U.S. Environmental Protection Agency (EPA)-designated Maumee River Area of Concern. The broad objective of the project is to evaluate how hydrologically reconnecting a previously diked wetland impacts fish, mollusks, and other biota and affects nutrient transport, nutrient cycling, water quality, flood storage, and many other abiotic conditions. The results from this project suggest large system-wide benefits from sustainable reestablishment of lake-driven hydrology in this and other similar systems. We comprehensively sampled water chemistry, fish, birds, plants, and invertebrates in Crane Creek coastal wetlands, Pool 2A (a reference diked wetland), and Pool 2B (the reconnected wetland) in 2010 and 2011 to: 1) Characterize spatial and seasonal patterns for these parameters. 2) Examine ecosystem response to the opening of a water-control structure that allows fish passage Our sampling efforts have yielded data that reveal striking changes in water quality, hydrology, and fish assemblages in our experimental unit (2B). Prior to the reconnection, the water chemistry in pools 2A and 2B were very similar. Afterwards, we found that the water chemistry in reconnected Pool 2B was more

77 FR 52701 - Board on Coastal Engineering Research

Science.gov (United States)

2012-08-30

... Environment and Human Health, and panel presentations dealing with Challenges to Ports and Navigation and Challenges to Beaches and Coastal Risk. Presentations dealing with Challenges to Ports and Navigation include Strategic Environmental Issues in Southeastern Dredging Operations; Mobile Bay Sediment Management Program...

Remote sensing and aerial photography for delineation and management of coastal ecosystems

Digital Repository Service at National Institute of Oceanography (India)

Jagtap, T.G.

sensing data. may provide necessary information to the planners and researchers. interested in the 11 .. coastal ecosystems. Mismanagement or lack of management of coastal zones may result in the loss of marine ecosystems, influencing erosion and the sea..., topographic maps and other resources. The effective management and research of coastal zones, require information on coastal landforms, wetlands, shoreline changes, sediment and current pattern, which can easily be obtained from the satellite data. Coastal...

Nearshore marine fish diversity in southern California using trawl information from the Southern California Coastal Water Research Project.

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This is a point file of mean fish diversity within 5 minute grid cells. The Shannon Index of diversity was calculated from Southern California Coastal Water Research...

NASA COAST and OCEANIA Airborne Missions in Support of Ecosystem and Water Quality Research in the Coastal Zone

Science.gov (United States)

Guild, Liane S.; Hooker, Stanford B.; Kudela, Raphael; Morrow, John; Russell, Philip; Myers, Jeffrey; Dunagan, Stephen; Palacios, Sherry; Livingston, John; Negrey, Kendra;

Seasonal variations in C:N:Si:Ca:P:Mg:S:K:Fe relationships of seston from Norwegian coastal water: Impact of extreme offshore forcing during winter-spring 2010.

Science.gov (United States)

Erga, Svein Rune; Haugen, Stig Bjarte; Bratbak, Gunnar; Egge, Jorun Karin; Heldal, Mikal; Mork, Kjell Arne; Norland, Svein

2017-11-20

The aim of this study was to reveal the relative content of C, N, Ca, Si, P, Mg, K, S and Fe in seston particles in Norwegian coastal water (NCW), and how it relates to biological and hydrographic processes during seasonal cycles from October 2009-March 2012. The following over all stoichiometric relationship for the time series was obtained: C 66 N 11 Si 3.4 Ca 2.3 P 1 Mg 0.73 S 0.37 K 0.35 Fe 0.30 , which is novel for marine waters. A record-breaking (187-year record) negative North Atlantic Oscillation (NAO) index caused extreme physical forcing on the Norwegian Coastal Current Water (NCCW) during the winter 2009-2010, and the inflow and upwelling of saline Atlantic water (AW) in the fjord was thus extraordinary during late spring-early summer in 2010. The element concentrations in fjord seston particles responded strongly to this convection, revealed by maximum values of all elements, except Fe, exceeding average values with 10.8 × for Ca, 9.3 for K, 5.3 for S, 5.1 for Mg, 4.6 for Si, 4.0 for P, 3.8 for C, and 3.3 for N and Fe. This indicates that the signature of the Atlantic inflow was roughly two times stronger for Ca and K than for the others, probably connected with peaks in coccolithophorids and diatoms. There is, however, 1.5 × more of Si than Ca contained in the seston, which could be due to a stronger dominance of diatoms than coccolithophorids, confirming their environmental fitness. In total our data do not indicate any severe nutrient limitation with respect to N, P and Fe, but accumulation of iron by Fe-sequestering bacteria might at times reduce the availability of the dissolved Fe-fraction. There is a high correlation between most of the measured elements, except for Ca, which together with Fe only weakly correlated with the other elements. It is to be expected that environmental alterations in NCW related to climate change will influence the seston elemental composition, but the full effect of this will be strongly dependent on the future

Global patterns of phytoplankton dynamics in coastal ecosystems

Science.gov (United States)

Paerl, H.; Yin, Kedong; Cloern, J.

2011-01-01

Scientific Committee on Ocean Research Working Group 137 Meeting; Hangzhou, China, 17-21 October 2010; Phytoplankton biomass and community structure have undergone dramatic changes in coastal ecosystems over the past several decades in response to climate variability and human disturbance. These changes have short- and long-term impacts on global carbon and nutrient cycling, food web structure and productivity, and coastal ecosystem services. There is a need to identify the underlying processes and measure the rates at which they alter coastal ecosystems on a global scale. Hence, the Scientific Committee on Ocean Research (SCOR) formed Working Group 137 (WG 137), "Global Patterns of Phytoplankton Dynamics in Coastal Ecosystems: A Comparative Analysis of Time Series Observations" (http://wg137.net/). This group evolved from a 2007 AGU-sponsored Chapman Conference entitled "Long Time-Series Observations in Coastal Ecosystems: Comparative Analyses of Phytoplankton Dynamics on Regional to Global Scales.".

Coastal Geographic Structures in Coastal-Marine Environmental Management

Science.gov (United States)

Baklanov, P. Ya.; Ganzei, K. S.; Ermoshin, V. V.

2018-01-01

It has been proposed to distinguish the coastal geographic structures consisting of a spatial combination of three interconnected and mutually conditioned parts (coastal-territorial, coastal, coastal-marine), which are interlinked with each other by the cumulative effect of real-energy flows. Distinguishing specific resource features of the coastal structures, by which they play a connecting role in the complex coastalmarine management, has been considered. The main integral resource feature of the coastal structures is their connecting functions, which form transitional parts mutually connecting the coastal-territorial and coastalmarine environmental management.

Quaternary geophysical framework of the northeastern North Carolina coastal system

Science.gov (United States)

Thieler, E.R.; Foster, D.S.; Mallinson, D.M.; Himmelstoss, E.A.; McNinch, J.E.; List, J.H.; Hammar-Klose, E.S.

2013-01-01

The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that mapped the Quaternary geologic framework of the estuaries, barrier islands, and inner continental shelf. This information provides a basis to understand the linkage between geologic framework, physical processes, and coastal evolution at time scales from storm events to millennia. The study area attracts significant tourism to its parks and beaches, contains a number of coastal communities, and supports a local fishing industry, all of which are impacted by coastal change. Knowledge derived from this research program can be used to mitigate hazards and facilitate effective management of this dynamic coastal system.

Investigating the salinization and freshening processes of coastal groundwater resources in Urmia aquifer, NW Iran.

Science.gov (United States)

Amiri, Vahab; Nakhaei, Mohammad; Lak, Razyeh; Kholghi, Majid

2016-04-01

This paper presents the results of an assessment about interaction between Urmia Lake (UL) and coastal groundwater in the Urmia aquifer (UA). This aquifer is the most significant contributor to the freshwater supply of the coastal areas. The use of hydrochemical facies can be very useful to identify the saltwater encroachment or freshening phases in the coastal aquifers. In this study, the analysis of salinization/freshening processes was carried out through the saturation index (SI), ionic deltas (Δ), binary diagrams, and hydrochemical facies evolution (HFE) diagram. Based on the Gibbs plot, the behavior of the major ions showed that the changes in the chemical composition of the groundwater are mainly controlled by the water-soil/rock interaction zone and few samples are relatively controlled by evaporation. A possible explanation for this phenomenon is that the deposited chloride and sulfate particles can form the minor salinity source in some coastal areas when washed down by precipitation. The SI calculations showed that all groundwater samples, collected in these periods, show negative saturation indices, which indicate undersaturation with respect to anhydrite, gypsum, and halite. In addition, except in a few cases, all other samples showed the undersaturation with respect to the carbonate minerals such as aragonite, calcite, and dolomite. Therefore, these minerals are susceptible to dissolution. In the dry season, the SI calculations showed more positive values with respect to dolomite, especially in the northern part of UA, which indicated a higher potential for precipitation and deposition of dolomite. The percentage of saltwater in the groundwater samples of Urmia plain was very low, ranging between 0.001 and 0.79 % in the wet season and 0.0004 and 0.81 % in the dry season. The results of HFE diagram, which was taken to find whether the aquifer was in the saltwater encroachment phase or in the freshening phase, indicated that except for a few wells

Global land–ocean linkage: direct inputs of nitrogen to coastal waters via submarine groundwater discharge

International Nuclear Information System (INIS)

Beusen, A H W; Slomp, C P; Bouwman, A F

2013-01-01

The role of submarine groundwater discharge (SGD), the leakage of groundwater from aquifers into coastal waters, in coastal eutrophication has been demonstrated mostly for the North American and European coastlines, but poorly quantified in other regions. Here, we present the first spatially explicit global estimates of N inputs via SGD to coastal waters and show that it has increased from about 1.0 to 1.4 Tg of nitrate (NO 3 -N) per year over the second half of the 20th century. Since this increase is not accompanied by an equivalent increase of groundwater phosphorus (P) and silicon (Si), SGD transport of nitrate is an important factor for the development of harmful algal blooms in coastal waters. Groundwater fluxes of N are linked to areas with high runoff and intensive anthropogenic activity on land, with Southeast Asia, parts of North and Central America, and Europe being hot spots. (letter)

Pwani Yetu: Issue 4. April 1999.Tanzania Coastal Management Partnership.

OpenAIRE

Tanzania Coastal Management Partnership

1999-01-01

The Newsletter of the Tanzania Coastal Management Partnership - Pwani Yetu - 'our coast', is produced every other month in both Kiswahili and English and circulated to all coastal management partners from national level, coastal communities and the private sector. Pwani Yetu reports on coastal and marine activities, including issues on conservation, environment, and social economic development. 'Research Group' TCMP.

Coastal Structures

DEFF Research Database (Denmark)

Oumeraci, H.; Burcharth, H. F.; Rouck, J. De

1995-01-01

The paper attempts to present an overview of five research projects supported by the Commission of the European Communities, Directorate General XII, under the MAST 2- Programme (Marine Sciences and Technology), with the overall objective of contributing to the development of improved rational me...... methods for the design of coastal structures....

The Coastal Ocean Prediction Systems program: Understanding and managing our coastal ocean. Volume 1: Strategic summary

Energy Technology Data Exchange (ETDEWEB)

1990-05-15

The proposed COPS (Coastal Ocean Prediction Systems) program is concerned with combining numerical models with observations (through data assimilation) to improve our predictive knowledge of the coastal ocean. It is oriented toward applied research and development and depends upon the continued pursuit of basic research in programs like COOP (Coastal Ocean Processes); i.e., to a significant degree it is involved with ``technology transfer`` from basic knowledge to operational and management applications. This predictive knowledge is intended to address a variety of societal problems: (1) ship routing, (2) trajectories for search and rescue operations, (3) oil spill trajectory simulations, (4) pollution assessments, (5) fisheries management guidance, (6) simulation of the coastal ocean`s response to climate variability, (7) calculation of sediment transport, (8) calculation of forces on structures, and so forth. The initial concern is with physical models and observations in order to provide a capability for the estimation of physical forces and transports in the coastal ocean. For all these applications, there are common needs for physical field estimates: waves, tides, currents, temperature, and salinity, including mixed layers, thermoclines, fronts, jets, etc. However, the intent is to work with biologists, chemists, and geologists in developing integrated multidisciplinary prediction systems as it becomes feasible to do so. From another perspective, by combining observations with models through data assimilation, a modern approach to monitoring is provided through whole-field estimation.

Analysis of Si/SiGe Heterostructure Solar Cell

Directory of Open Access Journals (Sweden)

Ashish Kumar Singh

2014-01-01

Full Text Available Sunlight is the largest source of carbon-neutral energy. Large amount of energy, about 4.3 × 1020 J/hr (Lewis, 2005, is radiated because of nuclear fusion reaction by sun, but it is unfortunate that it is not exploited to its maximum level. Various photovoltaic researches are ongoing to find low cost, and highly efficient solar cell to fulfil looming energy crisis around the globe. Thin film solar cell along with enhanced absorption property will be the best, so combination of SiGe alloy is considered. The paper presented here consists of a numerical model of Si/Si1-xGex heterostructure solar cell. The research has investigated characteristics such as short circuit current density (Jsc, generation rate (G, absorption coefficient (α, and open circuit voltage (Voc with optimal Ge concentration. The addition of Ge content to Si layer will affect the property of material and can be calculated with the use of Vegard’s law. Due to this, short circuit current density increases.

International cooperation for integrated management of coastal regions

International Nuclear Information System (INIS)

Bosc, E.; Houlbreque, F.; Boisson, F.; Scholten, J.; Betti, M.

2010-01-01

Coastal zones which comprise < 20% of the earth surface are one of the most dynamic areas of the world. Housing more than 50% of the earth's population, the coastal zones are affected by natural and anthropogenic induced pressures which challenge the sustainability of the coastal environment and its resources. Most of the environmental pressures originate from outside the coastal zones thus requiring an inter-regional approach for coastal environmental assessments. It is one of the missions of the Marine Environment Laboratories (MEL) of the International Atomic Energy Agency to assist Member States in coastal zone management by applying nuclear and isotopic techniques. These techniques are used in many ways at MEL to enhance the understanding of marine ecosystems and to improve their management and protection. The article gives an overview of MEL's current marine coastal projects and research activities. (author)

Iron Availability Influences Silicon Isotope Fractionation in Two Southern Ocean Diatoms (Proboscia inermis and Eucampia antarctica and a Coastal Diatom (Thalassiosira pseudonana

Directory of Open Access Journals (Sweden)

Scott Meyerink

2017-07-01

Full Text Available The fractionation of silicon (Si isotopes was measured in two Southern Ocean diatoms (Proboscia inermis and Eucampia Antarctica and a coastal diatom (Thalassiosira pseudonana that were grown under varying iron (Fe concentrations. Varying Fe concentrations had no effect on the Si isotope enrichment factor (ε in T. pseudonana, whilst E. Antarctica and P. inermis exhibited significant variations in the value of ε between Fe-replete and Fe-limited conditions. Mean ε values in P. inermis and E. Antarctica decreased from (± 1SD −1.11 ± 0.15‰ and −1.42 ± 0.41 ‰ (respectively under Fe-replete conditions, to −1.38 ± 0.27 ‰ and −1.57 ± 0.5 ‰ (respectively under Fe-limiting conditions. These variations likely arise from adaptations in diatoms arising from the nutrient status of their environment. T. pseudonana is a coastal clone typically accustomed to low Si but high Fe conditions whereas E. Antarctica and P. inermis are typically accustomed to High Si, High nitrate low Fe conditions. Growth induced variations in silicic acid (Si(OH4 uptake arising from Fe-limitation is the likely mechanism leading to Si-isotope variability in E. Antarctica and P. inermis. The multiplicative effects of species diversity and resource limitation (e.g., Fe on Si-isotope fractionation in diatoms can potentially alter the Si-isotope composition of diatom opal in diatamaceous sediments and sea surface Si(OH4. This work highlights the need for further in vitro studies into intracellular mechanisms involved in Si(OH4 uptake, and the associated pathways for Si-isotope fractionation in diatoms.

Low-temperature magnetotransport in Si/SiGe heterostructures on 300 mm Si wafers

Science.gov (United States)

Scappucci, Giordano; Yeoh, L.; Sabbagh, D.; Sammak, A.; Boter, J.; Droulers, G.; Kalhor, N.; Brousse, D.; Veldhorst, M.; Vandersypen, L. M. K.; Thomas, N.; Roberts, J.; Pillarisetty, R.; Amin, P.; George, H. C.; Singh, K. J.; Clarke, J. S.

Undoped Si/SiGe heterostructures are a promising material stack for the development of spin qubits in silicon. To deploy a qubit into high volume manufacturing in a quantum computer requires stringent control over substrate uniformity and quality. Electron mobility and valley splitting are two key electrical metrics of substrate quality relevant for qubits. Here we present low-temperature magnetotransport measurements of strained Si quantum wells with mobilities in excess of 100000 cm2/Vs fabricated on 300 mm wafers within the framework of advanced semiconductor manufacturing. These results are benchmarked against the results obtained in Si quantum wells deposited on 100 mm Si wafers in an academic research environment. To ensure rapid progress in quantum wells quality we have implemented fast feedback loops from materials growth, to heterostructure FET fabrication, and low temperature characterisation. On this topic we will present recent progress in developing a cryogenic platform for high-throughput magnetotransport measurements.

Effect of Nuclear Reactions on the Properties of Al-Mg-Si Alloys after Long-Time Exploitation in Research Reactors

CERN Document Server

Hofmann, A; Szteke, W; Hajewska, E; Wagner, T; Semina, V K

2004-01-01

Effect of fast neutron ($E>$ 0.1~?eV) irradiation on the mechanical properties and fracture morphology of the Al-Mg-Si alloys (PAR-1 and ???-1) after 40 years of exploitation in research nuclear reactors has been studied. Tested specimens were cut from structural elements of reactor EWA ($\\acute{\\rm S}$wierk, Poland). Irradiation induces degradation in mechanical properties, namely yield strength and ultimate strength increase, but elongation reduces. The mechanical property changes are caused by ageing of Al--Mg--Si alloy. During irradiation Si is formed from Al by the Al($n, \\gamma $)Si reaction. The presence of Si might cause strengthening of the Al--Mg--Si alloys by increasing precipitation of Mg$_{2}$Si or pure Si in the Al matrix. Post-irradiation activity studies of EWA reactor structural elements show that the high-activity $^{60}$Co and $^{65}$Zn isotopes have been formed by the nuclear reactions.

Effect of nuclear reactions on the properties of Al-Mg-Si alloys after long-time exploitation in research reactors

International Nuclear Information System (INIS)

Hofman, A.; Didyk, A.Yu.; Semina, V.K.; Szteke, W.; Hajewska, E.; Wagner, T.

2004-01-01

Effect of fast neutron (E > 0.1 MeV) irradiation on the mechanical properties and fracture morphology of the Al-Mg-Si alloys (PAR-1 and CAB-1) after 40 years of exploitation in research nuclear reactors has been studied. Tested specimens were cut from structural elements of reactor EWA (Swierk, Poland). Irradiation induces degradation in mechanical properties, namely yield strength and ultimate strength increase, but elongation reduces. The mechanical property changes are caused by ageing of Al-Mg-Si alloys. During irradiation Si is formed from Al by the Al(n, γ)Si reaction. The presence of Si might cause strengthening of the Al-Mg-Si alloys by increasing precipitation of Mg 2 Si or pure Si in the Al matrix. Post-irradiation activity studies of EWA reactor structural elements show that the high-activity 60 Co and 65 Zn isotopes have been formed by the nuclear reactions

The coastal landscape of the river of silver basis for management

International Nuclear Information System (INIS)

Martinez, A.; Fernandez, E.; Cendom, A.; Vila, L.

2013-01-01

A complex of morphogenic, ecologic and cultural factors converge in coastal landscape modelling. The goal of this research is to identify the coastal environment as a water-land interphase in the Rio de la Plata, Uruguay. The area of work is within Punta Gorda, Colonia Department, and Maldonado River, in the Maldonado Department. An integrated landscape approach is used to interpret the complex of natural areas. The knowledge of natural complex is the goal of this research using the vegetation dynamic as an expression of site condition. Cartography at scale 1:50.000, colour composition of Landsat images at scale 1:100.000 (1994), aerial photographs at scale 1:10.000 (1994), are the source of information. A methodology of three components was organized: a typology of the coastal border, scale 1:500.000, a littoral morphology analysis using maps and aerial photographs, scale 1:10.000 and the coastal landscape, scale 1:100.000. A land cover legend was organized to integrate: geomorphology, vegetation and human intervention. It has 12 classes y 4 subclasses of land cover. This information was integrated in an analysis of an ideal coastal outline that represents the ideal disposition of the landscape elements in a cross and vertical perspective. The final goal of this research is an inventory of coastal uniform sectors. The research was performed within an approach of environmental factors equilibrium, such as geomorphology, environment, biologic and anthropogenic, and natural’s process in progress. Specific and general coastal problems are identified. A conceptual coastal landscape approach, a coastal cartography and setting of landscape units are the final products

Toward a Global Classification of Coastal Anthromes

Directory of Open Access Journals (Sweden)

Eli D. Lazarus

2017-02-01

Full Text Available Given incontrovertible evidence that humans are the most powerful agents of environmental change on the planet, research has begun to acknowledge and integrate human presence and activity into updated descriptions of the world’s biomes as “anthromes”. Thus far, a classification system for anthromes is limited to the terrestrial biosphere. Here, I present a case for the consideration and validity of coastal anthromes. Every coastal environment on Earth is subject to direct and indirect human modification and disturbance. Despite the legacy, ubiquity, and pervasiveness of human interactions with coastal ecosystems, coastal anthromes still lack formal definition. Following the original argument and framework for terrestrial anthromes, I outline a set of coastal anthrome classifications that dovetail with terrestrial and marine counterparts. Recognising coastal environments as complex and increasingly vulnerable anthropogenic systems is a fundamental step toward understanding their modern dynamics—and, by extension, realising opportunities for and limits to their resilience.

Research Progress of Optical Fabrication and Surface-Microstructure Modification of SiC

Directory of Open Access Journals (Sweden)

Fang Jiang

2012-01-01

Full Text Available SiC has become the best candidate material for space mirror and optical devices due to a series of favorable physical and chemical properties. Fine surface optical quality with the surface roughness (RMS less than 1 nm is necessary for fine optical application. However, various defects are present in SiC ceramics, and it is very difficult to polish SiC ceramic matrix with the 1 nm RMS. Surface modification of SiC ceramics must be done on the SiC substrate. Four kinds of surface-modification routes including the hot pressed glass, the C/SiC clapping, SiC clapping, and Si clapping on SiC surface have been reported and reviewed here. The methods of surface modification, the mechanism of preparation, and the disadvantages and advantages are focused on in this paper. In our view, PVD Si is the best choice for surface modification of SiC mirror.

Future coastal population growth and exposure to sea-level rise and coastal flooding--a global assessment.

Directory of Open Access Journals (Sweden)

Barbara Neumann

Full Text Available Coastal zones are exposed to a range of coastal hazards including sea-level rise with its related effects. At the same time, they are more densely populated than the hinterland and exhibit higher rates of population growth and urbanisation. As this trend is expected to continue into the future, we investigate how coastal populations will be affected by such impacts at global and regional scales by the years 2030 and 2060. Starting from baseline population estimates for the year 2000, we assess future population change in the low-elevation coastal zone and trends in exposure to 100-year coastal floods based on four different sea-level and socio-economic scenarios. Our method accounts for differential growth of coastal areas against the land-locked hinterland and for trends of urbanisation and expansive urban growth, as currently observed, but does not explicitly consider possible displacement or out-migration due to factors such as sea-level rise. We combine spatially explicit estimates of the baseline population with demographic data in order to derive scenario-driven projections of coastal population development. Our scenarios show that the number of people living in the low-elevation coastal zone, as well as the number of people exposed to flooding from 1-in-100 year storm surge events, is highest in Asia. China, India, Bangladesh, Indonesia and Viet Nam are estimated to have the highest total coastal population exposure in the baseline year and this ranking is expected to remain largely unchanged in the future. However, Africa is expected to experience the highest rates of population growth and urbanisation in the coastal zone, particularly in Egypt and sub-Saharan countries in Western and Eastern Africa. The results highlight countries and regions with a high degree of exposure to coastal flooding and help identifying regions where policies and adaptive planning for building resilient coastal communities are not only desirable but essential

Future coastal population growth and exposure to sea-level rise and coastal flooding--a global assessment.

Science.gov (United States)

Neumann, Barbara; Vafeidis, Athanasios T; Zimmermann, Juliane; Nicholls, Robert J

2015-01-01

Coastal zones are exposed to a range of coastal hazards including sea-level rise with its related effects. At the same time, they are more densely populated than the hinterland and exhibit higher rates of population growth and urbanisation. As this trend is expected to continue into the future, we investigate how coastal populations will be affected by such impacts at global and regional scales by the years 2030 and 2060. Starting from baseline population estimates for the year 2000, we assess future population change in the low-elevation coastal zone and trends in exposure to 100-year coastal floods based on four different sea-level and socio-economic scenarios. Our method accounts for differential growth of coastal areas against the land-locked hinterland and for trends of urbanisation and expansive urban growth, as currently observed, but does not explicitly consider possible displacement or out-migration due to factors such as sea-level rise. We combine spatially explicit estimates of the baseline population with demographic data in order to derive scenario-driven projections of coastal population development. Our scenarios show that the number of people living in the low-elevation coastal zone, as well as the number of people exposed to flooding from 1-in-100 year storm surge events, is highest in Asia. China, India, Bangladesh, Indonesia and Viet Nam are estimated to have the highest total coastal population exposure in the baseline year and this ranking is expected to remain largely unchanged in the future. However, Africa is expected to experience the highest rates of population growth and urbanisation in the coastal zone, particularly in Egypt and sub-Saharan countries in Western and Eastern Africa. The results highlight countries and regions with a high degree of exposure to coastal flooding and help identifying regions where policies and adaptive planning for building resilient coastal communities are not only desirable but essential. Furthermore, we

Future Coastal Population Growth and Exposure to Sea-Level Rise and Coastal Flooding - A Global Assessment

Science.gov (United States)

Neumann, Barbara; Vafeidis, Athanasios T.; Zimmermann, Juliane; Nicholls, Robert J.

2015-01-01

Coastal zones are exposed to a range of coastal hazards including sea-level rise with its related effects. At the same time, they are more densely populated than the hinterland and exhibit higher rates of population growth and urbanisation. As this trend is expected to continue into the future, we investigate how coastal populations will be affected by such impacts at global and regional scales by the years 2030 and 2060. Starting from baseline population estimates for the year 2000, we assess future population change in the low-elevation coastal zone and trends in exposure to 100-year coastal floods based on four different sea-level and socio-economic scenarios. Our method accounts for differential growth of coastal areas against the land-locked hinterland and for trends of urbanisation and expansive urban growth, as currently observed, but does not explicitly consider possible displacement or out-migration due to factors such as sea-level rise. We combine spatially explicit estimates of the baseline population with demographic data in order to derive scenario-driven projections of coastal population development. Our scenarios show that the number of people living in the low-elevation coastal zone, as well as the number of people exposed to flooding from 1-in-100 year storm surge events, is highest in Asia. China, India, Bangladesh, Indonesia and Viet Nam are estimated to have the highest total coastal population exposure in the baseline year and this ranking is expected to remain largely unchanged in the future. However, Africa is expected to experience the highest rates of population growth and urbanisation in the coastal zone, particularly in Egypt and sub-Saharan countries in Western and Eastern Africa. The results highlight countries and regions with a high degree of exposure to coastal flooding and help identifying regions where policies and adaptive planning for building resilient coastal communities are not only desirable but essential. Furthermore, we

Saprobic analysis to Marina coastal, Semarang city

Science.gov (United States)

Nuriasih, D. M.; Anggoro, S.; Haeruddin

2018-02-01

Semarang city is one of coastal city in Indonesia, that antropogenic activities have impact to coastal of Semarang, including Marina beach. Therefore, it is important to study the quality of seawater related with antropogenic activities. The research purpose was to analyze the saprobic level of Marina beach as an indicator of marine pollution. This case study research used survey method. Purposive method was used for sampling the seawater at five stations at the beach. This research can be concluded that TSI (Tropic Saprobic Index) higher than standard that indicated the Marina Beach Seawaters polution at level of β - Mesosaprobic.

Study on water quality around mangrove ecosystem for coastal rehabilitation

Science.gov (United States)

Guntur, G.; Sambah, A. B.; Arisandi, D. M.; Jauhari, A.; Jaziri, A. A.

2018-01-01

Coastal ecosystems are vulnerable to environmental degradation including the declining water quality in the coastal environment due to the influence of human activities where the river becomes one of the input channels. Some areas in the coastal regions of East Java directly facing the Madura Strait indicate having experienced the environmental degradation, especially regarding the water quality. This research was conducted in the coastal area of Probolinggo Regency, East Java, aiming to analyze the water quality as the basis for coastal rehabilitation planning. This study was carried out using survey and observation methods. Water quality measurement results were analyzed conforming to predetermined quality standards. The coastal area rehabilitation planning as a means to restore the degraded water quality parameters is presumably implemented through mangrove planting. Thus, the mangrove mapping was also devised in this research. Based on 40 sampling points, the results illustrate that according to the quality standard, the water quality in the study area is likely to be deteriorated. On account of the mapping analysis of mangrove distribution in the study area, the rehabilitation of the coastal zone can be done through planning the mangrove forest plantation. The recommended coastal area maintenance is a periodic water quality observation planning in the river region which is divided into three zones to monitor the impact of fluctuating changes in land use or human activities on the coastal water quality.

Presentation of Coastal Environmental Management Plan by using ...

African Journals Online (AJOL)

The provision of environment management plan and formulating the environmental strategies of coastal regions are the most essential measures required for the integrated management of coastal regions. For this purpose, this research has been conducted using two goal-oriented and problem-oriented approaches in ...

U-Mo/Al-Si interaction: Influence of Si concentration

International Nuclear Information System (INIS)

Allenou, J.; Palancher, H.; Iltis, X.; Cornen, M.; Tougait, O.; Tucoulou, R.; Welcomme, E.; Martin, Ph.; Valot, C.; Charollais, F.; Anselmet, M.C.; Lemoine, P.

2010-01-01

Within the framework of the development of low enriched nuclear fuels for research reactors, U-Mo/Al is the most promising option that has however to be optimised. Indeed at the U-Mo/Al interfaces between U-Mo particles and the Al matrix, an interaction layer grows under irradiation inducing an unacceptable fuel swelling. Adding silicon in limited content into the Al matrix has clearly improved the in-pile fuel behaviour. This breakthrough is attributed to an U-Mo/Al-Si protective layer around U-Mo particles appeared during fuel manufacturing. In this work, the evolution of the microstructure and composition of this protective layer with increasing Si concentrations in the Al matrix has been investigated. Conclusions are based on the characterization at the micrometer scale (X-ray diffraction and energy dispersive spectroscopy) of U-Mo7/Al-Si diffusion couples obtained by thermal annealing at 450 deg. C. Two types of interaction layers have been evidenced depending on the Si content in the Al-Si alloy: the threshold value is found at about 5 wt.% but obviously evolves with temperature. It has been shown that for Si concentrations ranging from 2 to 10 wt.%, the U-Mo7/Al-Si interaction is bi-layered and the Si-rich part is located close to the Al-Si for low Si concentrations (below 5 wt.%) and close to the U-Mo for higher Si concentrations. For Si weight fraction in the Al alloy lower than 5 wt.%, the Si-rich sub-layer (close to Al-Si) consists of U(Al, Si) 3 + UMo 2 Al 20 , when the other sub-layer (close to U-Mo) is silicon free and made of UAl 3 and U 6 Mo 4 Al 43 . For Si weight concentrations above 5 wt.%, the Si-rich part becomes U 3 (Si, Al) 5 + U(Al, Si) 3 (close to U-Mo) and the other sub-layer (close to Al-Si) consists of U(Al, Si) 3 + UMo 2 Al 20 . On the basis of these results and of a literature survey, a scheme is proposed to explain the formation of different types of ILs between U-Mo and Al-Si alloys (i.e. different protective layers).

Sea Level Change and Coastal Climate Services: The Way Forward

Directory of Open Access Journals (Sweden)

Gonéri Le Cozannet

2017-10-01

Full Text Available For many climate change impacts such as drought and heat waves, global and national frameworks for climate services are providing ever more critical support to adaptation activities. Coastal zones are especially in need of climate services for adaptation, as they are increasingly threatened by sea level rise and its impacts, such as submergence, flooding, shoreline erosion, salinization and wetland change. In this paper, we examine how annual to multi-decadal sea level projections can be used within coastal climate services (CCS. To this end, we review the current state-of-the art of coastal climate services in the US, Australia and France, and identify lessons learned. More broadly, we also review current barriers in the development of CCS, and identify research and development efforts for overcoming barriers and facilitating their continued growth. The latter includes: (1 research in the field of sea level, coastal and adaptation science and (2 cross-cutting research in the area of user interactions, decision making, propagation of uncertainties and overall service architecture design. We suggest that standard approaches are required to translate relative sea level information into the forms required to inform the wide range of relevant decisions across coastal management, including coastal adaptation.

Adaptation Decision Support: An Application of System Dynamics Modeling in Coastal Communities

Institute of Scientific and Technical Information of China (English)

Daniel Lane; Shima Beigzadeh; Richard Moll

2017-01-01

This research develops and applies a system dynamics (SD) model for the strategic evaluation of environmental adaptation options for coastal communities.The article defines and estimates asset-based measures for community vulnerability,resilience,and adaptive capacity with respect to the environmental,economic,social,and cultural pillars of the coastal community under threat.The SD model simulates the annual multidimensional dynamic impacts of severe coastal storms and storm surges on the community pillars under alternative adaptation strategies.The calculation of the quantitative measures provides valuable information for decision makers for evaluating the alternative strategies.The adaptation strategies are designed model results illustrated for the specific context of the coastal community of Charlottetown,Prince Edward Island,Canada.The dynamic trend of the measures and model sensitivity analyses for Charlottetown-facing increased frequency of severe storms,storm surges,and sea-level rise-provide impetus for enhanced community strategic planning for the changing coastal environment.This research is presented as part of the International Community-University Research Alliance C-Change project "Managing Adaptation to Environmental Change in Coastal Communities:Canada and the Caribbean" sponsored by the Social Science and Humanities Research Council of Canada and the International Development Resource Centre.

Hurricane Isaac: observations and analysis of coastal change

Science.gov (United States)

Guy, Kristy K.; Stockdon, Hilary F.; Plant, Nathaniel G.; Doran, Kara S.; Morgan, Karen L.M.

2013-01-01

Understanding storm-induced coastal change and forecasting these changes require knowledge of the physical processes associated with a storm and the geomorphology of the impacted coastline. The primary physical process of interest is sediment transport that is driven by waves, currents, and storm surge associated with storms. Storm surge, which is the rise in water level due to the wind, barometric pressure, and other factors, allows both waves and currents to impact parts of the coast not normally exposed to these processes. Coastal geomorphology reflects the coastal changes associated with extreme-storm processes. Relevant geomorphic variables that are observable before and after storms include sand dune elevation, beach width, shoreline position, sediment grain size, and foreshore beach slope. These variables, in addition to hydrodynamic processes, can be used to quantify coastal change and are used to predict coastal vulnerability to storms (Stockdon and others, 2007). The U.S. Geological Survey (USGS) National Assessment of Coastal Change Hazards (NACCH) project (http://coastal.er.usgs.gov/national-assessment/) provides hazard information to those concerned about the Nation’s coastlines, including residents of coastal areas, government agencies responsible for coastal management, and coastal researchers. Extreme-storm research is a component of the NACCH project (http://coastal.er.usgs.gov/hurricanes/) that includes development of predictive understanding, vulnerability assessments using models, and updated observations in response to specific storm events. In particular, observations were made to determine morphological changes associated with Hurricane Isaac, which made landfall in the United States first at Southwest Pass, at the mouth of the Mississippi River, at 0000 August 29, 2012 UTC (Coordinated Universal Time) and again, 8 hours later, west of Port Fourchon, Louisiana (Berg, 2013). Methods of observation included oblique aerial photography

siRNAmod: A database of experimentally validated chemically modified siRNAs.

Science.gov (United States)

Dar, Showkat Ahmad; Thakur, Anamika; Qureshi, Abid; Kumar, Manoj

2016-01-28

Small interfering RNA (siRNA) technology has vast potential for functional genomics and development of therapeutics. However, it faces many obstacles predominantly instability of siRNAs due to nuclease digestion and subsequently biologically short half-life. Chemical modifications in siRNAs provide means to overcome these shortcomings and improve their stability and potency. Despite enormous utility bioinformatics resource of these chemically modified siRNAs (cm-siRNAs) is lacking. Therefore, we have developed siRNAmod, a specialized databank for chemically modified siRNAs. Currently, our repository contains a total of 4894 chemically modified-siRNA sequences, comprising 128 unique chemical modifications on different positions with various permutations and combinations. It incorporates important information on siRNA sequence, chemical modification, their number and respective position, structure, simplified molecular input line entry system canonical (SMILES), efficacy of modified siRNA, target gene, cell line, experimental methods, reference etc. It is developed and hosted using Linux Apache MySQL PHP (LAMP) software bundle. Standard user-friendly browse, search facility and analysis tools are also integrated. It would assist in understanding the effect of chemical modifications and further development of stable and efficacious siRNAs for research as well as therapeutics. siRNAmod is freely available at: http://crdd.osdd.net/servers/sirnamod.

Paradigms in the Recovery of Estuarine and Coastal Ecosystems

OpenAIRE

Duarte, Carlos M.; Borja, Ángel; Carstensen, Jacob; Elliott, Michael S.; Krause-Jensen, Dorte; Marbà, Núria

2015-01-01

© 2013, Coastal and Estuarine Research Federation. Following widespread deterioration of coastal ecosystems since the 1960s, current environmental policies demand ecosystem recovery and restoration. However, vague definitions of recovery and untested recovery paradigms complicate efficient stewardship of coastal ecosystems. We critically examine definitions of recovery and identify and test the implicit paradigms against well-documented cases studies based on a literature review. The study hi...

First results of the research project MIRAMAR, Innovative Methodologies for Coastal Environmental Monitoring and Analysis

Science.gov (United States)

Rovere, A.; Casella, E.; Vacchi, M.; Mucerino, L.; Pedroncini, A.; Ferrari, M.; Firpo, M.

2013-12-01

A large part of the Mediterranean coastlines are strongly affected by coastal erosion. This is mainly due to human impact, natural hazards and their mutual interaction. All along the Regione Liguria coastlines (Northwestern Mediterranean), significant problems of coastal erosion are reported since the '60s. In this study, we focus on the coastal area between Albenga and Savona, where dramatic coastal retreat of ~2 m y-1 has been inferred from comparison of historic maps and older aerial pictures. Beach monitoring is essential in order to understand the mechanisms of evolution of soft coasts, and the rates of erosion. Traditional beach monitoring techniques involve topographic and bathymetric surveys of the emerged and submerged beach, and/or aerial photos repeated in time and compared through geographical information systems. A major problem of this kind of approach is the high economic cost. This often leads to increase the time lag between successive monitoring campaigns to reduce survey costs, with the consequence of fragmenting the information available for coastal zone management. MIRAMar is a project funded by Regione Liguria through the PO CRO European Social Fund, and it has two main objectives: i) to study and develop an innovative technique, relatively low-cost, to monitor the evolution of the shoreline using low-altitude Unmanned Aerial Vehicle (UAV) photos; ii) to study the impact of different type of storm events on a vulnerable coastal tract subject to coastal erosion using also the data collected by the UAV instrument. To achieve these aims we use a drone with its hardware and software suit, traditional survey techniques (bathymetric surveys, topographic GPS surveys and GIS techniques) and we implement a numerical modeling chain (coupling hydrodynamic, wave and sand transport modules) in order to study the impact of different type of storm events on a vulnerable coastal tract subject to coastal erosion. Aerial picture of one of the beaches studied

Radiation emission from wrinkled SiGe/SiGe nanostructure

Czech Academy of Sciences Publication Activity Database

Fedorchenko, Alexander I.; Cheng, H. H.; Sun, G.; Soref, R. A.

2010-01-01

Roč. 96, č. 11 (2010), s. 113104-113107 ISSN 0003-6951 Institutional research plan: CEZ:AV0Z20760514 Keywords : SiGe wrinkled nanostructures * si-based optical emitter * synchrotron radiation Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.820, year: 2010 http://apl.aip.org/resource/1/applab/v96/i11/p113104_s1?isAuthorized=no

Coastal terrorism: using tabletop discussions to enhance coastal community infrastructure through relationship building.

Science.gov (United States)

Richter, Jane; Livet, Melanie; Stewart, Jill; Feigley, Charles E; Scott, Geoff; Richter, Donna L

2005-11-01

The unique vulnerability of the nation's ports to terrorist attacks and other major disasters requires development of specialized training approaches that integrate and connect critical stakeholders. In 2003, the University of South Carolina Center for Public Health Preparedness developed and held its first Coastal Terrorism workshop in conjunction with the National Oceanic and Atmospheric Administration. Key federal, regional, state, and coastal agency leaders were invited to the 2-day event to explore, in a no-risk environment, the crucial role that public health agencies would play in a covert biological agent incident aboard a cruise ship. The incident began as a possible outbreak of a Norwalk-like viral agent; however, as the scenario unfolded, evidence of a terrorist plot emerged. This immediately shifted the scenario from a public health-dominated incident to one directed by law enforcement. Communication and coordination issues surfaced illustrating potential conflicts between disciplines and jurisdictions in terms of roles and responsibilities of responding agencies. The goals of the workshop were to facilitate communication and interagency networking among coastal stakeholders while assessing their training and research needs and increasing their familiarity with resources and protocols regarding a bioterrorist coastal event. Positive systems changes were observed.

A typology of coastal researchers’ modes of interactions with stakeholders

Directory of Open Access Journals (Sweden)

Milligan Jessica

2004-09-01

Full Text Available A feature of the management of natural resources in the coastal zone is that it involves multiple stakeholders. It has been suggested that the effectiveness of coastal management relies on the cooperation of this multitude of stakeholders in decision-making. This study reports on the findings of an investigation into the modes of interaction used by coastal researchers to communicate with stakeholders. A qualitative research methodology was used through both telephone and in-depth face-toface interviews to elucidate the mechanisms of interaction and, in turn, produce a typology of interaction modes. It was found that there were five main modes of interaction: Limited; Mediator Achieved; Key Stakeholder; Full Interaction and Mixed and that the discipline area in which the researcher worked did not dictate their preferred mode of interaction. It was concluded that although there are a number of limitations to effective participation, these interactions have significant implications for meaningful participation in the management of coastal resources.

Personal care products and steroid hormones in the Antarctic coastal environment associated with two Antarctic research stations, McMurdo Station and Scott Base.

Science.gov (United States)

Emnet, Philipp; Gaw, Sally; Northcott, Grant; Storey, Bryan; Graham, Lisa

2015-01-01

Pharmaceutical and personal care products (PPCPs) are a major source of micropollutants to the aquatic environment. Despite intense research on the fate and effects of PPCPs in temperate climates, there is a paucity of data on their presence in polar environments. This study reports the presence of selected PPCPs in sewage effluents from two Antarctic research stations, the adjacent coastal seawater, sea ice, and biota. Sewage effluents contained bisphenol-A, ethinylestradiol, estrone, methyl triclosan, octylphenol, triclosan, and three UV-filters. The maximum sewage effluent concentrations of 4-methyl-benzylidene camphor, benzophenone-1, estrone, ethinylestradiol, and octylphenol exceeded concentrations previously reported. Coastal seawaters contained bisphenol-A, octylphenol, triclosan, three paraben preservatives, and four UV-filters. The sea ice contained a similar range and concentration of PPCPs as the seawater. Benzophenone-3 (preferential accumulation in clams), estradiol, ethinylestradiol, methyl paraben (preferential accumulation in fish, with concentrations correlating negatively with fillet size), octylphenol, and propyl paraben were detected in biota samples. PPCPs were detected in seawater and biota at distances up to 25 km from the research stations WWTP discharges. Sewage effluent discharges and disposal of raw human waste through sea ice cracks have been identified as sources of PPCPs to Antarctic coastal environments. Copyright © 2014 Elsevier Inc. All rights reserved.

China's coastal wetlands: conservation history, implementation efforts, existing issues and strategies for future improvement.

Science.gov (United States)

Sun, Zhigao; Sun, Wenguang; Tong, Chuan; Zeng, Congsheng; Yu, Xiang; Mou, Xiaojie

2015-06-01

China has approximately 5.80×10(6)ha coastal wetlands by 2014, accounting for 10.82% of the total area of natural wetlands. Healthy coastal wetland ecosystems play an important role in guaranteeing the territory ecological security and the sustainable development of coastal zone in China. In this paper, the natural geography and the past and present status of China's coastal wetlands were introduced and the five stages (1950s-1970s, 1980s-1991, 1992-2002, 2003-2010 and 2011-present) of China's coastal wetlands conservation from the foundation of the People's Republic in 1949 to present were distinguished and reviewed. Over the past decades, China has made great efforts in coastal wetland conservation, as signified by the implementation of coastal wetland restoration projects, the construction of coastal wetland nature reserves, the practice of routine ecological monitoring and two national wetland surveys, the promulgation of local wetland conservation statutes and specific regulations, the coordination mechanism to enhance management capacity, the wide development of coastal wetland research and public participation, and the extensive communication to strengthen international cooperation. Nonetheless, six major issues recently emerged in China's coastal wetland conservation are evidently existed, including the increasing threats of pollution and human activities, the increasing adverse effects of threaten factors on ecosystem function, the increasing threats of coastal erosion and sea-level rising, the insufficient funding for coastal wetlands conservation, the imperfect legal and management system for coastal wetlands, and the insufficient education, research and international cooperation. Although the threats and pressures on coastal wetlands conservation are still apparent, the future of China's coastal wetlands looks promising since the Chinese government understands that the sustainable development in coastal zone requires new attitudes, sound policies and

Using Virtualization to Integrate Weather, Climate, and Coastal Science Education

Science.gov (United States)

Davis, J. R.; Paramygin, V. A.; Figueiredo, R.; Sheng, Y.

2012-12-01

To better understand and communicate the important roles of weather and climate on the coastal environment, a unique publically available tool is being developed to support research, education, and outreach activities. This tool uses virtualization technologies to facilitate an interactive, hands-on environment in which students, researchers, and general public can perform their own numerical modeling experiments. While prior efforts have focused solely on the study of the coastal and estuary environments, this effort incorporates the community supported weather and climate model (WRF-ARW) into the Coastal Science Educational Virtual Appliance (CSEVA), an education tool used to assist in the learning of coastal transport processes; storm surge and inundation; and evacuation modeling. The Weather Research and Forecasting (WRF) Model is a next-generation, community developed and supported, mesoscale numerical weather prediction system designed to be used internationally for research, operations, and teaching. It includes two dynamical solvers (ARW - Advanced Research WRF and NMM - Nonhydrostatic Mesoscale Model) as well as a data assimilation system. WRF-ARW is the ARW dynamics solver combined with other components of the WRF system which was developed primarily at NCAR, community support provided by the Mesoscale and Microscale Meteorology (MMM) division of National Center for Atmospheric Research (NCAR). Included with WRF is the WRF Pre-processing System (WPS) which is a set of programs to prepare input for real-data simulations. The CSEVA is based on the Grid Appliance (GA) framework and is built using virtual machine (VM) and virtual networking technologies. Virtualization supports integration of an operating system, libraries (e.g. Fortran, C, Perl, NetCDF, etc. necessary to build WRF), web server, numerical models/grids/inputs, pre-/post-processing tools (e.g. WPS / RIP4 or UPS), graphical user interfaces, "Cloud"-computing infrastructure and other tools into a

Participatory research towards co-management: lessons from artisanal fisheries in coastal Uruguay.

Science.gov (United States)

Trimble, Micaela; Berkes, Fikret

2013-10-15

Participatory research has become increasingly common in natural resources management. Even though participatory research is considered a strategy to facilitate co-management, there is little empirical evidence supporting this. The objective of the present paper is to analyze the contributions of participatory research to help encourage the emergence of co-management, based on a case study in Piriápolis artisanal fishery in coastal Uruguay (where management has been top-down). We argue that participatory research involving artisanal fishers, government, and other stakeholders (university scientists and NGOs) can be a key stimulus towards co-management. We build this argument by considering "seven faces" by which co-management can be analyzed: (1) as power sharing; (2) as institution building; (3) as trust building; (4) as process; (5) as learning and knowledge co-production; (6) as problem solving; and (7) as governance. Our findings show that participatory research had an impact on these various faces: (1) power was shared when making research decisions; (2) a multi-stakeholder group (POPA), with a common vision and goals, was created; (3) trust among participants increased; (4) the process of group formation was valued by participants; (5) stakeholders learned skills for participation; (6) two problem-solving exercises were conducted; and (7) a diversity of stakeholders of the initial problem identified by fishers (sea lions' impact on long-line fishery) participated in the process. The case shows that participatory research functions as a platform which enhances learning and knowledge co-production among stakeholders, paving the way towards future co-management. Copyright © 2013 Elsevier Ltd. All rights reserved.

Nuclear and isotopic techniques for the characterization of submarine groundwater discharge in coastal zones. Results of a coordinated research project 2001-2006

International Nuclear Information System (INIS)

2007-07-01

Submarine groundwater discharge (SGD) is now recognized as an important pathway between land and sea. As such, this flow may contribute to the biogeochemical and other marine budgets of nearshore waters. These discharges typically display significant spatial and temporal variability, making direct assessments difficult. Groundwater seepage is patchy, diffuse, temporally variable, and may involve multiple aquifers. Thus, the measurement of its magnitude and associated chemical fluxes is a challenging enterprise. An initiative on SGD characterization was developed by the IAEA and UNESCO in 2000 as a 5-year plan to assess methodologies and importance of SGD for coastal zone management. The IAEA component included a Coordinated Research Project (CRP) on Nuclear and Isotopic Techniques for the Characterization of Submarine Groundwater Discharge (SGD) in Coastal Zones, carried out jointly by the IAEA's Isotope Hydrology Section in Vienna and the Marine Environment Laboratory in Monaco, together with 9 laboratories from 8 countries. In addition to the IAEA, the Intergovernmental Oceanographic Commission (IOC) and the International Hydrological Programme (IHP) have provided support. This overall effort originally grew from a project sponsored by the Scientific Committee on Ocean Research (SCOR) who established a Working Group (112) on SGD. The activities included joint meetings (Vienna 2000, 2002, and 2005; Syracuse, Italy, 2001; and Monaco 2004), sampling expeditions (Australia 2000; Sicily 2001 and 2002; New York 2002; Brazil 2003; and Mauritius 2005), joint analytical work, data evaluation, and preparation of joint publications. The objectives of the CRP included the improvement of capabilities for water resources and environmental management of coastal zones; application of recently developed nuclear and isotopic techniques suitable for quantitative estimation of various components of SGD; understanding of the influence of SGD on coastal processes and on groundwater

77 FR 62494 - Proposed Information Collection; Comment Request; Evaluations of Coastal Zone Management Act...

Science.gov (United States)

2012-10-15

... Collection; Comment Request; Evaluations of Coastal Zone Management Act Programs--State Coastal Management... request is for a new information collection. The Coastal Zone Management Act of 1972, as amended (CZMA; 16 U.S.C. 1451 et seq.) requires that state coastal management programs and national estuarine research...

Empowerment and Coastal Community Participation on Mangrove Development in Pati Regency

Directory of Open Access Journals (Sweden)

Sutrisno

2015-03-01

Full Text Available Development of mangrove plants is a very complex effort to implement, because the activity needs accommodative nature of the community around the coastal. This study aims to determine the government's role in the empowerment of coastal communities and public participation in the development of coastal mangrove plant in Pati regency. The research used descriptive approach with primary data was obtained from survey toward 282 respondents whom directly involved in mangrove development, while secondary data were obtained from relevant documents. The data were analyzed using descriptive method. The results of research are: (1 The score of government’s role on coastal community empowerment and mangrove development is 49.94 (categorized as enough. (2 Community empowerment on mangrove development get score 41.81 (categorized as enough.

The Arctic Coastal Erosion Problem

Energy Technology Data Exchange (ETDEWEB)

Frederick, Jennifer M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Thomas, Matthew Anthony [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bull, Diana L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jones, Craig A. [Integral Consulting Inc., San Francisco, CA (United States); Roberts, Jesse D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2016-09-01

Permafrost-dominated coastlines in the Arctic are rapidly disappearing. Arctic coastal erosion rates in the United States have doubled since the middle of the twentieth century and appear to be accelerating. Positive erosion trends have been observed for highly-variable geomorphic conditions across the entire Arctic, suggesting a major (human-timescale) shift in coastal landscape evolution. Unfortunately, irreversible coastal land loss in this region poses a threat to native, industrial, scientific, and military communities. The Arctic coastline is vast, spanning more than 100,000 km across eight nations, ten percent of which is overseen by the United States. Much of area is inaccessible by all-season roads. People and infrastructure, therefore, are commonly located near the coast. The impact of the Arctic coastal erosion problem is widespread. Homes are being lost. Residents are being dispersed and their villages relocated. Shoreline fuel storage and delivery systems are at greater risk. The U.S. Department of Energy (DOE) and Sandia National Laboratories (SNL) operate research facilities along some of the most rapidly eroding sections of coast in the world. The U.S. Department of Defense (DOD) is struggling to fortify coastal radar sites, operated to ensure national sovereignty in the air, against the erosion problem. Rapid alterations to the Arctic coastline are facilitated by oceanographic and geomorphic perturbations associated with climate change. Sea ice extent is declining, sea level is rising, sea water temperature is increasing, and permafrost state is changing. The polar orientation of the Arctic exacerbates the magnitude and rate of the environmental forcings that facilitate coastal land area loss. The fundamental mechanics of these processes are understood; their non-linear combination poses an extreme hazard. Tools to accurately predict Arctic coastal erosion do not exist. To obtain an accurate predictive model, a coupling of the influences of

Building Blocks: A Quantitative Approach for Evaluating Coastal Vulnerability

Directory of Open Access Journals (Sweden)

Komali Kantamaneni

2017-11-01

Full Text Available Climate change and associated factors such as global and regional sea-level rise; the upsurge in high-intensity flooding events; and coastal erosion are pulse and press disturbances that threaten to increase landslides in coastal regions. Under these circumstances; a rigorous framework is required to evaluate coastal vulnerability in order to plan for future climate change scenarios. A vast majority of coastal vulnerability assessments across the globe are evaluated at the macro level (city scale but not at the micro level (small town scale; particularly in the United Kingdom (UK. In order to fill this vital research gap; the current study established a coastal vulnerability index termed here as the Micro Town Coastal Vulnerability Index (MTCVI and then applied it to Barton-on-Sea; which is a small coastal town of the Hampshire region; England; UK. MTCVI was evaluated for Barton-on-Sea coastal vulnerability by integrating both novel and existing parameters. Results suggest that the entire shoreline frontage (2 km exhibits very high coastal vulnerability and is prone to various coastal hazards such as landslides; erosion; and wave intrusion. This suggests that Barton-on-Sea coastal amenities will require a substantial improvement in shoreline protection measures. In this study; GIS (geographic information system coastal vulnerability and landslide maps were generated; and these maps can be used by the local authorities; district councils; coastal engineers; and planners to improve and design coastal management strategies under the climate change scenarios. Meanwhile; the methodology used in this study could also be applied to any other suitable location in the world depending on the availability of the data.

Advances in coastal disasters risk management : Lessons from the 2011 Tohoku tsunami

NARCIS (Netherlands)

Jonkman, S.N.; Yasuda, T.; Tsimopoulou, V.; Kawai, H.; Kato, F.

2012-01-01

The earthquake and tsunami of March 2011 led to death and destruction in coastal areas in Japan. A seminar was held in June 2012 for Japanese and Dutch coastal researchers to discuss lessons for the management of the risks in coastal areas associated with tsunamis, typhoons and storm surges. The

Coastal Innovation Imperative

Directory of Open Access Journals (Sweden)

Bruce C. Glavovic

2013-03-01

Full Text Available This is the second of two articles that explores the coastal innovation paradox and imperative. Paradoxically, innovation is necessary to escape the vulnerability trap created by past innovations that have degraded coastal ecosystems and imperil coastal livelihoods. The innovation imperative is to reframe and underpin business and technology with coherent governance innovations that lead to social transformation for coastal sustainability. How might coastal management help to facilitate this transition? It is argued that coastal management needs to be reconceptualised as a transformative practice of deliberative coastal governance. A foundation comprising four deliberative or process outcomes is posited. The point of departure is to build human and social capital through issue learning and improved democratic attitudes and skills. Attention then shifts to facilitating community-oriented action and improving institutional capacity and decision-making. Together, these endeavours enable improved community problem-solving. The ultimate process goal is to build more collaborative communities. Instituting transformative deliberative coastal governance will help to stimulate innovations that chart new sustainability pathways and help to resolve the coastal problems. This framework could be adapted and applied in other geographical settings.

Proceedings of the 79th Meeting of the Coastal Engineering Research Board, 6-10 June 2005 (Anchorage, AK)

Science.gov (United States)

2006-09-29

integrated Coastal Community Vulnerability and Adaptation Program focused on improving the resilience of coastal communities to natural hazards and...in sharp contrast to the situation of a coastal community facing a serious erosion threat. The nature of the problem may be pretty clear, but the...products to improve the preparedness of communities, businesses, and government entities. As described in Section 8 of S.50, this Coastal

Use of the Cumbrian coastal area

International Nuclear Information System (INIS)

1991-12-01

The primary objective of the research was to establish the recreational usage made of the Cumbrian coastal area. Observations of the numbers of adults and children in each area included in the study were undertaken, as well as an interview survey among adults which identified patterns of use by different groups. The interview survey comprised 7070 interviews, 80% of which were with residents of, rather than visitors to, Cumbria. Additional investigations and analyses were conducted to: determine hours of occupancy at coastal areas; observe usage made of particular areas outside the locations and times of the main survey; assess the usage made of coastal areas and inland waterways by members of the public likely to be excluded from the main study (eg. bird watchers, water-sport participants). (author)

Hurricane Ike: Observations and Analysis of Coastal Change

Science.gov (United States)

Doran, Kara S.; Plant, Nathaniel G.; Stockdon, Hilary F.; Sallenger, Asbury H.; Serafin, Katherine A.

2009-01-01

Understanding storm-induced coastal change and forecasting these changes require knowledge of the physical processes associated with the storm and the geomorphology of the impacted coastline. The primary physical processes of interest are the wind field, storm surge, and wave climate. Not only does wind cause direct damage to structures along the coast, but it is ultimately responsible for much of the energy that is transferred to the ocean and expressed as storm surge, mean currents, and large waves. Waves and currents are the processes most responsible for moving sediments in the coastal zone during extreme storm events. Storm surge, the rise in water level due to the wind, barometric pressure, and other factors, allows both waves and currents to attack parts of the coast not normally exposed to those processes. Coastal geomorphology, including shapes of the shoreline, beaches, and dunes, is equally important to the coastal change observed during extreme storm events. Relevant geomorphic variables include sand dune elevation, beach width, shoreline position, sediment grain size, and foreshore beach slope. These variables, in addition to hydrodynamic processes, can be used to predict coastal vulnerability to storms The U.S. Geological Survey's (USGS) National Assessment of Coastal Change Hazards Project (http://coastal.er.usgs.gov/hurricanes), strives to provide hazard information to those interested in the Nation's coastlines, including residents of coastal areas, government agencies responsible for coastal management, and coastal researchers. As part of the National Assessment, observations were collected to measure coastal changes associated with Hurricane Ike, which made landfall near Galveston, Texas, on September 13, 2008. Methods of observation included aerial photography and airborne topographic surveys. This report documents these data-collection efforts and presents qualitative and quantitative descriptions of hurricane-induced changes to the shoreline

Large-scale coastal behaviour in relation to coastal zone management

NARCIS (Netherlands)

Stive, M.J.F.

1990-01-01

The development of coastal erosion management - addressing typical traditional erosion problems - towards coastal zone management addressing the evaluation of alternative solutions to guarantee a variety of coastal zone functions on their economic time scale - has necessitated the formulation of

Library Development Strategy for The Community at Coastal Areas

Science.gov (United States)

Suharso, Putut; Sudardi, Bani; Teguh Widodo, Sahid; Kusumo Habsari, Sri

2018-02-01

This study aims to reveal various phenomena of the existence of libraries in coastal areas, especially to pay a particular attention to the relation power between various interests of the library, especially the managers and the community as the users and to explore how both parties understand and imagine the idea of library through the developing the library as a center of learning and skill development. The design of the research is explorative qualitative. Applying case study approach, the location of this research is in a coastal area, in the floating library of Tambak Lorok coastal, Semarang. Data are collected through observation and in-depth interviews with several parties involved. To examine the validity of data, this study applies a triangulation technique of sources focusing on key informants living in the community. The result of this research shows that the existence of library in the coastal area is more than the common belief to the function of library. Although finding shows that the government’s attitude to support the development of the library has been as expected through producing some regulations, the response of the community to the development of the library is far beyond the expectation. Some drawbacks found are in the handling of library management which is still lack of implementation from the initial planning and the absence of integrated coastal resources management resulted from low understanding and mastery of policy makers and implementers of the national library program. However, the community has developed a community-based management which is an approach that has been widely used in various regions as an effort to empower themselves through utilizing any existed facilities, in this case is the library. Community has successfully produced an initiative of developing integrated coastal resource management programs which are still hard to find in Indonesia, especially those involving library institutions.

Irradiation project of SiC/SiC fuel pin 'INSPIRE': Status and future plan

International Nuclear Information System (INIS)

Kohyama, Akira; Kishimoto, Hirotatsu

2015-01-01

After the March 11 Disaster in East-Japan, Research and Development towards Ensuring Nuclear Safety Enhancement for LWR becomes a top priority R and D in nuclear energy policy of Japan. The role of high temperature non-metallic materials, such as SiC/SiC, is becoming important for the advanced nuclear reactor systems. SiC fibre reinforced SiC composite has been recognised to be the most attractive option for the future, now, METI fund based project, INSPIRE, has been launched as 5-year termed project at OASIS in Muroran Institute of Technology aiming at early realisation of this system. INSPIRE is the irradiation project of SiC/SiC fuel pins aiming to accumulate material, thermal, irradiation effect data of NITE-SiC/SiC in BWR environment. Nuclear fuel inserted SiC/SiC fuel pins are planned to be installed in the Halden reactor. The project includes preparing the NITE-SiC/SiC tubes, joining of end caps, preparation of rigs to control the irradiation environment to BWR condition and the instruments to measure the condition of rigs and pins in operation. Also, basic neutron irradiation data will be accumulated by SiC/SiC coupon samples currently under irradiation in BR2. The output from this project may present the potentiality of NITE-SiC/SiC fuel cladding with the first stage fuel-cladding interaction. (authors)

COASTAL COMMUNITY PARTICIPATION IN KELURAHAN SUKOLILO, BULAK, BASED ON LOCAL ECONOMY

Directory of Open Access Journals (Sweden)

Dyah Kusuma Wardhani

2017-07-01

Full Text Available Kelurahan Sukolilo, Bulak Settlement is an area of fishermen settlement with great potential of resources such as fish and sea cucumber. Kelurahan Sukolilo also well known as Prominent Kampung in fish processed products. Despite having a great potential in marine resources, most of the fishermen still live in a low environmental and economic condition. Theres hould be effective environmental management in coastal area so the fiherman vulnerability can be reduced through a criteria of developing coastal area that is able to accomodate the fisherman economic activities. The researcher will apply community based development in developing coastal area criteria.. In this case community-based development approach needs to be developed in the management of coastal areas, especially for the improvement of the environmental quality. This is because the coastal characteristic and resources are very complex and diverse, so in the coastal area management should involve the local community directly. Community based management shows the importance of community participation in development planning and implementation. This research was in form of qualitative research, data sources obtained by primary and secondary data. Primary data were collected through observations, visual documentations and interview with the fishermen and fish processors. Secondary data were obtained from literature and theory. Research results showed that  level of community participation that need to be done in the development process using active participatory. Active participatory should be done through partnership and delegated power level to accomodate fishermen and fish processors activities and support sustainable environment. Co-working space for inhabitants is needed  to accomodate community activities related to water and odor and drying process and to create area to socialize

Food security assessment in the coastal area of Demak Regency

Science.gov (United States)

Harini, R.; Handayani, H. N.; Ramdani, F. R.

2018-04-01

Food security is an issue of national and global level. Food is a basic human need to live. Without food will threaten human life. This research was conducted in coastal area of Demak Regency. This research is to understand the potential of human resources, natural resources and assess the level of food security of coastal communities. The data used are primary data through interviews with the local community. Also used Secondary data from government agencies. Data analysis used qualitative and quantitative descriptive methods through graphs, tables and maps. The results showed that potential of human resources in Demak coastal area (Wedung, Purworejo, and Sidogemah villages) is low. It can be indicated from education level of respondents in Demak are elementary school and junior high school. Beside, total households income are about 2-4 million. This study found that the households sampled are 90% is food insecured households. The most of households in Demak coastal area are about 90% households include on insecurity food category.

Moessbauer and channeling experiments on TeSi and SmSi

International Nuclear Information System (INIS)

Kemerink, G.J.; Boerma, D.O.; Waard, H. de; Wit, J.C. de; Drentje, S.A.

1980-01-01

Considerable effort is made to obtain an insight in the structural and electronic properties of ion implanted elemental semiconductors. This research is strongly stimulated by the many applications of semi-conductor devices. We report here on Moessbauer studies of 129 TeSi and 153 SmSi, using the 27.8 keV transition in 129 I and the 103.2 keV transition in 153 Eu, respectively, and on channeling experiments on 128 TeSi and 152 SmSi with a 2 MeV α-beam from the Groningen Van de Graaff generator. In the Moessbauer experiments we used Cu 129 I and EuF 3 .1/2H 2 O as absorber materials. Source and absorber were held at 4.2 K. The implantations were generally done at room temperature with an implantation energy of 100-115 keV. For the Moessbauer and channeling measurements we applied similar Si single crystals and the same implantation and annealing conditions. Crystals with low doses could only be investigated with the Moessbauer effect

Defense Coastal/Estuarine Research Program (DCERP) Baseline Monitoring Plan

Science.gov (United States)

2007-09-19

climatological stress (e.g., temperature, drought) and shorter-term air pollutant stress (oxidants and metals ). Heavy metals of fine PM have been...speciation of the fine and coarse PM fractions will allow distinction between different PM sources such as wind blown soil dust, including dust...emitting 12% of the total PM2.5 mass (U.S. EPA, 2004b). Source apportionment modeling of PM2.5 mass concentrations from 24 Speciation Defense Coastal

Egyptian coastal regions development through economic diversity for its coastal cities

Directory of Open Access Journals (Sweden)

Tarek AbdeL-Latif

2012-12-01

This study examines the structure of the coastal cities industry, the main types, the impacts (economic, environmental, and social of coastal cities, and the local trends in development in the Egyptian coastal cities and its regions. It will also analyze coastal and marine tourism in several key regions identified because of the diversity of life they support, and the potential destruction they could face. This paper confirms that economic diversification in coastal cities is more effective than developments in only one economic sector, even if this sector is prominent and important.

The use of U3Si2 dispersed in aluminum in plate-type fuel elements for research and test reactors

International Nuclear Information System (INIS)

Snelgrove, J.L.; Domagala, R.F.; Hofman, G.L.; Wiencek, T.C.; Copeland, G.L.; Hobbs, R.W.; Senn, R.L.

1987-10-01

A high-density fuel based on U 3 Si 2 dispersed in aluminum has been developed and tested for use in converting plate-type research and test reactors from the use of highly enriched uranium to the use of low-enriched uranium. Results of preirradiation testing and the irradiation and postirradiation examination of miniature fuel plates and full-sized fuel elements are summarized. Swelling of the U 3 Si 2 fuel particles is a linear function of the fission density in the particle to well beyond the fission density achievable in low-enriched fuels. U 3 Si 2 particle swelling rate is approximately the same as that of the commonly used UAl/sub x/ fuel particle. The presence of minor amounts of U 3 Si or uranium solid solution in the fuel result in greater, but still acceptable, fuel swelling. Blister threshold temperatures are at least as high as those of currently used fuels. An exothermic reaction occurs near the aluminum melting temperature, but the measured energy releases were low enough not to substantially worsen the consequences of an accident. U 3 Si 2 -aluminum dispersion fuel with uranium densities up to at least 4.8 Mg/m 3 is a suitable LEU fuel for typical plate-type research and test reactors. 42 refs., 28 figs., 7 tabs

COASTAL, Pacific, Washington

Data.gov (United States)

Federal Emergency Management Agency, Department of Homeland Security — Coastal study data as defined in FEMA Guidelines and Specifications, Appendix D: Guidance for Coastal Flooding Analyses and Mapping, submitted as a coastal study.

Monitoring Coastal Change after the Tsunami in Thailand

International Nuclear Information System (INIS)

Pantanahiran, W

2014-01-01

The tsunami on December 26, 2004 caused widespread devastation along the coast of Thailand, especially in Ban Nam Khem, Phang Nga province. This disaster claimed more than 941 lives, with 502 other people missing when the storm surge caught the residents of this area. The coastal geomorphology was impacted by this disaster. The objectives of the research were to study the effect of the tsunami on coastal change and the recovery of coastal areas. Six time-series datasets of aerial photographs and satellite images from 2002, 2004, 2005, 2006, 2009, and 2010 were compared using the Geographic Information System (GIS). The results showed the effect of the tsunami on the buildings in the area. Fifty-eight point sixty-three percent of the buildings in the urban area were destroyed by the tsunami and constructions was raised to 103.60% and 197.12% between 2004 and 2010, thus indicating the recovery of the local community. Geomorphological change in Ko Kho Khao (the island) was found after the tsunami disaster, including coastal erosion and coastal deposition. The balance of nature played a major role in controlling the erosion and deposition. The coastal deposits were the highest in 2005; however, deposition was not found in 2004. The erosion rate from 2002-2003 was the highest (48.10 meter per year) and higher than 2003-2004 (39.03 meters per year), 2004-2009 (15.64 meters per year) and 2009-2010 (29.49 meters per year). The coastal area was more severe eroded than the estuary area, and severe coastal erosion caused the loss of coastal area, approximately 0.28 ha. Severe coastal erosion has been repeatedly found since 2005 in the lower part of the area, and hard structures such as concrete seawalls might have been affected by coastal erosion. In addition, extrapolation of coastal erosion at the rate of 30 meters per year showed that the lower part of Ko Kho Khao should disappear in 2015

Simulation research on the effect of cooled EGR, supercharging and compression ratio on downsized SI engine knock

Science.gov (United States)

Shu, Gequn; Pan, Jiaying; Wei, Haiqiao; Shi, Ning

2013-03-01

Knock in spark-ignition(SI) engines severely limits engine performance and thermal efficiency. The researches on knock of downsized SI engine have mainly focused on structural design, performance optimization and advanced combustion modes, however there is little for simulation study on the effect of cooled exhaust gas recirculation(EGR) combined with downsizing technologies on SI engine performance. On the basis of mean pressure and oscillating pressure during combustion process, the effect of different levels of cooled EGR ratio, supercharging and compression ratio on engine dynamic and knock characteristic is researched with three-dimensional KIVA-3V program coupled with pressure wave equation. The cylinder pressure, combustion temperature, ignition delay timing, combustion duration, maximum mean pressure, and maximum oscillating pressure at different initial conditions are discussed and analyzed to investigate potential approaches to inhibiting engine knock while improving power output. The calculation results of the effect of just cooled EGR on knock characteristic show that appropriate levels of cooled EGR ratio can effectively suppress cylinder high-frequency pressure oscillations without obvious decrease in mean pressure. Analysis of the synergistic effect of cooled EGR, supercharging and compression ratio on knock characteristic indicates that under the condition of high supercharging and compression ratio, several times more cooled EGR ratio than that under the original condition is necessarily utilized to suppress knock occurrence effectively. The proposed method of synergistic effect of cooled EGR and downsizing technologies on knock characteristic, analyzed from the aspects of mean pressure and oscillating pressure, is an effective way to study downsized SI engine knock and provides knock inhibition approaches in practical engineering.

The use of Ground Penetrating Radar in coastal research, archeaological investigations, lake studies, peat layer measurments and applied research in Estonia

Science.gov (United States)

Vilumaa, Kadri; Tõnisson, Hannes; Orviku, Kaarel

2014-05-01

Ground Penetrating Radar (GPR) is mainly used for scientific research in coastal geology in the Institute of Ecology at Tallinn University. We currently use SIR-3000 radar with 100, 270 , 300 and 500 MHz antennae. Our main targets have been detecting the thickness of soil and sand layers and finding out the layers in coastal sediments which reflect extreme storm events. Our GPR studies in various settings have suggested that the internal structures of the ridge-dune complexes are dominated by numerous layers dipping in various directions. Such information helps us to reconstruct and understand prevailing processes during their formation (e.g. seaward dipping lamination in coastal ridge-dune complexes indicating cross-shore and wave-induced transport of the sediments). Currently, we are trying to elaborate methodology for distinguishing the differences between aeolian and wave transported sediments by using GPR. However, paludified landscapes (often covered by water), very rough surface (numerous bushes and soft surface), moderate micro topography has slowed this process significantly. Moreover, we have been able to use GPR during the winter period (applied on ice or snow) and compare the quality of our results with the measurements taken during the summer period. We have found that smooth surface (in winter) helps detecting very strong signal differences (border between different sediment types - sand, peat, silt, etc.) but reduces the quality of the signal to the level where the detection of sedimentation patterns within one material (e.g. tilted layers in sand) is difficult. We have carried out several other science-related studies using GPR. These studies include determining the thickness of peat layer in bogs (to calculate the volume of accumulated peat or to find most suitable locations for coring), measuring the thickness of mud and gyttja layer in lakes (to find most suitable locations for coring, reconstructing initial water level of the lake or calculating

From grey to green: Efficacy of eco-engineering solutions for nature-based coastal defence.

Science.gov (United States)

Morris, Rebecca L; Konlechner, Teresa M; Ghisalberti, Marco; Swearer, Stephen E

2018-05-01

Climate change is increasing the threat of erosion and flooding along coastlines globally. Engineering solutions (e.g. seawalls and breakwaters) in response to protecting coastal communities and associated infrastructure are increasingly becoming economically and ecologically unsustainable. This has led to recommendations to create or restore natural habitats, such as sand dunes, saltmarsh, mangroves, seagrass and kelp beds, and coral and shellfish reefs, to provide coastal protection in place of (or to complement) artificial structures. Coastal managers are frequently faced with the problem of an eroding coastline, which requires a decision on what mitigation options are most appropriate to implement. A barrier to uptake of nature-based coastal defence is stringent evaluation of the effectiveness in comparison to artificial protection structures. Here, we assess the current evidence for the efficacy of nature-based vs. artificial coastal protection and discuss future research needs. Future projects should evaluate habitats created or restored for coastal defence for cost-effectiveness in comparison to an artificial structure under the same environmental conditions. Cost-benefit analyses should take into consideration all ecosystem services provided by nature-based or artificial structures in addition to coastal protection. Interdisciplinary research among scientists, coastal managers and engineers is required to facilitate the experimental trials needed to test the value of these shoreline protection schemes, in order to support their use as alternatives to artificial structures. This research needs to happen now as our rapidly changing climate requires new and innovative solutions to reduce the vulnerability of coastal communities to an increasingly uncertain future. © 2018 John Wiley & Sons Ltd.

A Systems Approach Framework for Coastal Zones

Directory of Open Access Journals (Sweden)

Tom S. Hopkins

2011-12-01

Full Text Available This Special Feature Volume examines the potential value of the Systems Approach Framework (SAF as a methodological framework for the transition to sustainable development in coastal zones. This article provides insight on the Systems Approach, the theory behind it, and how its practical application to coastal zone systems (CZSs was developed. The SAF is about information for management through a focus on how to generate a higher, dynamic level of information about complex CZSs and how to render this information more useful to end users through a participatory suite of communication methods. The SAF is an open research methodology that investigates the function of systems in order to simulate specific issues or questions concerning their function. The research articles that are included in this Volume demonstrate examples of coupled multidisciplinary methods integrated into SAF simulations appropriate to a selected policy issue and to the social-environmental conditions of each Study Site Application. Their findings are not the result of funded research projects; instead, they are by-products of pilot applications conducted to develop and improve the SAF methodology. The final article of this Volume synthesizes these results in the context of the SAF as a higher level instrument for integrated coastal zone management.

Wave Overtopping at Coastal Structures

DEFF Research Database (Denmark)

Geeraearts, Jimmy; De Rouck, Julien; Troch, Peter

2006-01-01

The European research project CLASH (EVK3-CT-2001-00058) investigated wave overtopping at coastal structures. More specific it was to develop a generic prediction method for wave overtopping and to solve the problem of suspected scale effects. The paper summarizes the main results concerning...

Geomorphometry in coastal morphodynamics

Science.gov (United States)

Guisado-Pintado, Emilia; Jackson, Derek

2017-04-01

Geomorphometry is a cross-cutting discipline that has interwoven itself into multiple research themes due to its ability to encompass topographic quantification on many fronts. Its operational focus is largely defined as the extraction of land-surface parameters and earth surface characterisation. In particular, the coastal sciences have been enriched by the use of digital terrain production techniques both on land and in the nearshore/marine area. Numerous examples exist in which the utilisation of field instrumentation (e.g. LIDAR, GPS, Terrestrial Laser Scanning, multi-beam echo-sounders) are used for surface sampling and development of Digital Terrain Models, monitoring topographic change and creation of nearshore bathymetry, and have become central elements in modern investigations of coastal morphodynamics. The coastal zone is a highly dynamic system that embraces variable and at times, inter-related environments (sand dunes, sandy beaches, shoreline and nearshore) all of which require accurate and integrated monitoring. Although coastal studies can be widely diverse (with interconnected links to other related disciplines such as geology or biology), the characterisation of the landforms (coastal geomorphology) and associated processes (morphodynamics, hydrodynamics, aeolian processes) is perhaps where geomorphometry (topo-bathymetry quantification) is best highlighted. In this respect, many tools have been developed (or improved upon) for the acquisition of topographic data that now commands a high degree of accuracy, simplicity, and ultimately acquisition cost reduction. We present a series of field data acquisitions examples that have produced land surface characterisation using a range of techniques including traditional GPS surveys to more recent Terrestrial Laser Scanning and airborne LIDAR. These have been conducted within beach and dune environments and have helped describe erosion and depositional processes driven by wind and wave energy (high

Coastal vulnerability: climate change and natural hazards perspectives

Science.gov (United States)

Romieu, E.; Vinchon, C.

2009-04-01

. This concept is a great tool for policy makers to help managing their action and taking into account climate change (McFadden, et al. 2006). However, in those approaches, vulnerability is the output itself (cost of effective impacts, geomorphologic impacts…), but is not integrated it in a risk analysis. Furthermore, those studies emerged from a climatic perspective, which leads to consider climate change as a hazard or pressure whereas risk studies commonly consider hazards such as erosion and flooding, where climate change modifies the drivers of the hazard. 2) The natural hazards and socio economic perspectives In order to reduce impacts of natural hazards, decision makers need a complete risk assessment (probability of losses). Past studies on natural risks (landslide, earthquake...) highlighted the pertinence of defining risk as a combination of : (1)hazard occurrence and intensity, (2) exposition and (3)vulnerability of assets and population to this hazard (e.g. Douglas. 2007, Sarewitz, et al. 2003). Following the Renn and Klinke risk assessment frame, high uncertainties associated with coastal risks considering climatic and anthropic change highlights the importance of working on that concept of "vulnerability" (Klinke and Renn. 2002). Past studies on vulnerability assessment showed a frequently mentioned gap between "impact based" and "human based" points of view. It is nowadays a great issue for natural risk sciences. Many research efforts in FP7 projects such as MOVE and ENSURE focus on integrating the different dimensions of vulnerability (Turner, et al. 2003, Birkmann. 2006). Coastal risk studies highlight another issue of concern. We previously detailed the different use of the term "vulnerability" in the coastal context, quite different of the "natural risk's" use. Interaction of social, economic and physical sciences is considered within two french research projects (Vulsaco, Miseeva), in order to identify the vulnerability of a system to flooding or

Evaluating the human impact on groundwater quality discharging into a coastal reef lagoon

Science.gov (United States)

Rebolledo-Vieyra, M.; Hernandez-Terrones, L.; Soto, M.; Lecossec, A.; Monroy-Rios, E.

2008-12-01

The Eastern coast of the Yucatan Peninsula has the fastest growth rate in Mexico and groundwater is the only source of drinking water in the region. The consequences of the lack of proper infrastructure to collect and treat wastewater and the impact of human activities on the quality of groundwater are addressed. The groundwater in the coastal aquifer of Quintana Roo (SE Mexico) discharges directly into the ocean. In addition, the coral reef of the Eastern Yucatan Peninsula is part of the Mesoamerican Coral Reef System, one of the largest in the world. The interaction of the reef-lagoon hydraulics with the coastal aquifer of Puerto Morelos (NE Yucatan Peninsula), and a major input of NH4, SO4, SiO2, as a consequence of the use of septic tanks and the lack of modern wastewater treatment plants are presented. No seasonal parameters differences were observed, suggesting that groundwater composition reaching the reef lagoon is not changing seasonally. A conceptual model of the coastal aquifer was developed, in order to explain how the human activities are impacting directly on the groundwater quality that, potentially, will have a direct impact on the coral reef. The protection and conservation of coral reefs must be directly related with a policy of sound management of coastal aquifers and wastewater treatment.

Matrix densification of SiC composites by sintering process

International Nuclear Information System (INIS)

Kim, Young-Wook; Jang, Doo-Hee; Eom, Jung-Hye; Chun, Yong-Seong

2007-02-01

The objectives of this research are to develop a process for dense SiC fiber-SiC composites with a porosity of 5% or less and to develop high-strength SiC fiber-SiC composites with a strength of 500 MPa or higher. To meet the above objectives, the following research topics were investigated ; new process development for the densification of SiC fiber-SiC composites, effect of processing parameters on densification of SiC fiber-SiC composites, effect of additive composition on matrix microstructure, effects of additive composition and content on densification of SiC fiber-SiC composites, mechanical properties of SiC fiber-SiC composites, effect of fiber coating on densification and strength of SiC fiber-SiC composites, development of new additive composition. There has been a great deal of progress in the development of technologies for the processing and densification of SiC fiber-SiC composites and in better understanding of additive-densification-mechanical property relations as results of this project. Based on the progress, dense SiC fiber-SiC composites (≥97%) and high strength SiC fiber-SiC composites (≥600 MPa) have been developed. Development of 2D SiC fiber-SiC composites with a relative density of ≥97% and a strength of ≥600 MPa can be counted as a notable achievement

Present status of SiCf/SiC composites as low-activation structural materials of fusion reactor in Japan

International Nuclear Information System (INIS)

Kohyama, A.; Katoh, Y.; Hasegawa, A.; Noda, T.

2001-01-01

The outline of research subjects on SiCf/SiC composites to apply to the structural components of fusion reactors are described and present status on material development of SiCf/SiC composites in Japan is reviewed. Irradiation experiments of the composites using fission reactors conducted by international collaborations to clarify their radiation response and to optimize the fabrication processes are introduced. (author)

A Sociotechnical Systems Approach To Coastal Marine Spatial Planning

Science.gov (United States)

2016-12-01

SYSTEMS APPROACH TO COASTAL MARINE SPATIAL PLANNING by Tyler B. McDonald December 2016 Thesis Advisor: Karen Holness Co-Advisor: Tom...2016 3. REPORT TYPE AND DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE A SOCIOTECHNICAL SYSTEMS APPROACH TO COASTAL MARINE SPATIAL PLANNING...engineering perspective and specifically used a sociotechnical systems approach . The research investigated aquaculture permitting from the

75 FR 44938 - Atlantic Coastal Fisheries Cooperative Management Act Provisions; Atlantic Coastal Shark Fishery

Science.gov (United States)

2010-07-30

... Coastal Fisheries Cooperative Management Act Provisions; Atlantic Coastal Shark Fishery AGENCY: National... moratorium on fishing for Atlantic coastal sharks in the State waters of New Jersey. NMFS canceled the... Fisheries Commission's (Commission) Interstate Fishery Management Plan for Atlantic Coastal Sharks (Coastal...

Coastal Engineering

NARCIS (Netherlands)

Van der Velden, E.T.J.M.

1989-01-01

Introduction, waves, sediment transport, littoral transport, lonshore sediment transport, onshore-offshore sediment transport, coastal changes, dune erosion and storm surges, sedimentation in channels and trenches, coastal engineering in practice.

Ordering at Si(111)/o-Si and Si(111)/SiO2 Interfaces

DEFF Research Database (Denmark)

Robinson, I. K.; Waskiewicz, W. K.; Tung, R. T.

1986-01-01

X-ray diffraction has been used to measure the intensity profile of the two-dimensional rods of scattering from a single interface buried inside a bulk material. In both Si(111)/a-Si and Si(111)/SiO2 examples there are features in the perpendicular-momentum-transfer dependence which are not expec...... are not expected from an ideal sharp interface. The diffraction profiles are explained by models with partially ordered layers extending into the amorphous region. In the Si(111)/a-Si case there is clear evidence of stacking faults which are attributed to residual 7×7 reconstruction....

Challenges and potential solutions for European coastal ocean modelling

Science.gov (United States)

She, Jun; Stanev, Emil

2017-04-01

Coastal operational oceanography is a science and technological platform to integrate and transform the outcomes in marine monitoring, new knowledge generation and innovative technologies into operational information products and services in the coastal ocean. It has been identified as one of the four research priorities by EuroGOOS (She et al. 2016). Coastal modelling plays a central role in such an integration and transformation. A next generation coastal ocean forecasting system should have following features: i) being able to fully exploit benefits from future observations, ii) generate meaningful products in finer scales e.g., sub-mesoscale and in estuary-coast-sea continuum, iii) efficient parallel computing and model grid structure, iv) provide high quality forecasts as forcing to NWP and coastal climate models, v) resolving correctly inter-basin and inter-sub-basin water exchange, vi) resolving synoptic variability and predictability in marine ecosystems, e.g., for algae bloom, vi) being able to address critical and relevant issues in coastal applications, e.g., marine spatial planning, maritime safety, marine pollution protection, disaster prevention, offshore wind energy, climate change adaptation and mitigation, ICZM (integrated coastal zone management), the WFD (Water Framework Directive), and the MSFD (Marine Strategy Framework Directive), especially on habitat, eutrophication, and hydrographic condition descriptors. This presentation will address above challenges, identify limits of current models and propose correspondent research needed. The proposed roadmap will address an integrated monitoring-modelling approach and developing Unified European Coastal Ocean Models. In the coming years, a few new developments in European Sea observations can expected, e.g., more near real time delivering on profile observations made by research vessels, more shallow water Argo floats and bio-Argo floats deployed, much more high resolution sea level data from SWOT

Electrical instability of a-Si:H/SiN thin film transistors : a study at room temperature and low voltage stress

NARCIS (Netherlands)

Merticaru, A.R.

2004-01-01

The thesis shows the results of four years of research into the electrical stability of a-Si:H/SiN TFTs. Various methods of investigation of a-Si:H/SiN TFTs have been carried out in this thesis towards understanding the causes of degradation that shortens the transistor lifetime and narrows the

SI units in engineering and technology

CERN Document Server

Qasim, S H

2016-01-01

SI Units in Engineering and Technology focuses on the use of the International System of Units-Systeme International d'Unités (SI). The publication first elaborates on the SI, derivation of important engineering units, and derived SI units in science and engineering. Discussions focus on applied mechanics in mechanical engineering, electrical and magnetic units, stress and pressure, work and energy, power and force, and magnitude of SI units. The text then examines SI units conversion tables and engineering data in SI units. Tables include details on the sectional properties of metals in SI units, physical properties of important molded plastics, important physical constants expressed in SI units, and temperature, area, volume, and mass conversion. Tables that show the mathematical constants, standard values expressed in SI units, and Tex count conversion are also presented. The publication is a dependable source of data for researchers interested in the use of the International System of Units-Systeme Inter...

75 FR 9158 - Atlantic Coastal Fisheries Cooperative Management Act Provisions; Coastal Sharks Fishery

Science.gov (United States)

2010-03-01

... Coastal Fisheries Cooperative Management Act Provisions; Coastal Sharks Fishery AGENCY: National Marine... Commission's Interstate Fishery Management Plan (ISFMP) for Coastal Sharks. Subsequently, the Commission... New Jersey failed to carry out its responsibilities under the Coastal Sharks ISFMP, and if the...

COASTALT Project's contribution to the development and dissemination of coastal altimetry

Science.gov (United States)

Cipollini, P.; Benveniste, J.

2012-04-01

Satellite altimeters have been monitoring the global ocean for 20 years, with an excellent degree of accuracy; but in the coastal strip data are normally flagged as bad because of a number of technical problems, and therefore rejected. However this situation is rapidly changing: prompted by the tantalizing prospect of recovering 20 years of data over the coastal ocean, and encouraged by the improved suitability for coastal applications of new and future altimeters (like those on Cryosat-2, AltiKa and Sentinel-3), a lively community of researchers in coastal altimetry has coalesced in the last few years, and is developing techniques to recover useful measurements of sea level and significant wave height in the coastal strip, as well as implementing and promoting new applications. The major space agencies are strongly supporting R&D in this new field with initiatives like ESA's COASTALT (for Envisat) and CNES' PISTACH (for Jason-2). The coastal altimetry community holds regular workshops (see http://www.coastalt.eu/community) where the science and techniques of coastal altimetry are reviewed and various applications are showcased and discussed. The present contribution revisits briefly the many recent technical improvements that are contributing to the steady progress of this new field and in particular focuses on the results of the COASTALT project, which has recently concluded. COASTALT has been an excellent incubator of ideas and new techniques for the improvement of coastal altimetry: first of all it has contributed to establish user requirements for this new field, and it has defined detailed product specifications for the new coastal altimetry products and produced the relevant documentation. At the same time COASTALT has tackled the two main areas of improvement for coastal altimetry. These are: 1) retracking, i.e. fitting a waveform model to the waveforms to obtain an estimate of the geophysical parameters: and 2) designing and validating improved coastal

Do ENSO and Coastal Development Enhance Coastal Burial of Terrestrial Carbon?

Science.gov (United States)

Macreadie, Peter I; Rolph, Timothy C; Boyd, Ron; Schröder-Adams, Claudia J; Skilbeck, Charles G

2015-01-01

Carbon cycling on the east coast of Australia has the potential to be strongly affected by El Niño-Southern Oscillation (ENSO) intensification and coastal development (industrialization and urbanization). We performed paleoreconstructions of estuarine sediments from a seagrass-dominated estuary on the east coast of Australia (Tuggerah Lake, New South Wales) to test the hypothesis that millennial-scale ENSO intensification and European settlement in Australia have increased the transfer of organic carbon from land into coastal waters. Our data show that carbon accumulation rates within coastal sediments increased significantly during periods of maximum millennial-scale ENSO intensity ("super-ENSO") and coastal development. We suggest that ENSO and coastal development destabilize and liberate terrestrial soil carbon, which, during rainfall events (e.g., La Niña), washes into estuaries and becomes trapped and buried by coastal vegetation (seagrass in this case). Indeed, periods of high carbon burial were generally characterized as having rapid sedimentation rates, higher content of fine-grained sediments, and increased content of wood and charcoal fragments. These results, though preliminary, suggest that coastal development and ENSO intensification--both of which are predicted to increase over the coming century--can enhance capture and burial of terrestrial carbon by coastal ecosystems. These findings have important relevance for current efforts to build an understanding of terrestrial-marine carbon connectivity into global carbon budgets.

Implementation of remote sensing data in research of coastal dynamics at the Baydaratskaya Bay, Kara Sea

Science.gov (United States)

Kuznetsov, D. E.; Belova, N.; Noskov, A.; Ogorodov, S.

2011-12-01

The development of Arctic coastal regions is now in progress due to significant amount of hydrocarbon deposits discovered. In high latitudes, natural hazards such as coastal erosion and thermoerosion, deflation, linear erosion and thermal denudation, ice gouging can make petroleum production and transport unprofitable. A prominent feature of Kara Sea, as well as other Arctic seas, is the development of coast in permafrost conditions. Despite the long ice period (up to 9 months), during the ice free period coastal dynamics are very intensive. If pipeline landfall site occurs at a shore section with high retreat rate (1 - 3m/year and higher), danger of pipeline damage due to exposure, line sagging and mechanical deformations becomes high. Protective measures may appear inefficient, since shore sections with active coastal erosion are subject not only to bluff retreat, but also to nearshore zone and coastal slope erosion. Exposed pipeline sections also get in danger of sea ice effect. For correct definition of coastal dynamics setting we use dual approach. The first part is perennial instrumental monitoring of shore morphology, relying on system of benchmarks used for repeated measures, together with in-field geomorphologic expertise. Measures include direct observations and geodetic leveling onshore and echosounding offshore. Being the most precise method, direct measurements are expensive. The other drawback is that they can't give an overview of long-span tendencies of coastal evolution for prolonged shore sections, which is essential for shore deformation forecast complying with lifetime of structures (usually 30 to 50 years). This is where the importance of the 2nd part, analysis of the different time remote sensing data, becomes decisive. Most important sources of remote sensing data include Corona imagery from 1960s - 70s, aerial photos of different times (but most of them are inaccessible for Russian Arctic coast), Landsat imagery (covering a long time span

The Present Status of SiC/SiC R and D for Nuclear Application in Japan

International Nuclear Information System (INIS)

Kohyama, Akira

2011-01-01

SiC/SiC R and D for nuclear application in Japan is quite active under the coordinated activities of Atomic Energy Society of Japan's committee on 'Applications of Ceramic Materials for Advanced Nuclear Power Systems' and mainly government funded nuclear engineering/materials activities collaborating academia and industries. Start with the brief introduction of those activities, representing research activities are introduced. ITER and BA related SiC/SiC activities are emphasized, followed by introductions of extensive OASIS, Muroran Institute of Technology activities. The importance of international collaboration and strategic planning is mentioned.

SiC-Si as a support material for oxygen evolution electrode in PEM steam electrolysers

DEFF Research Database (Denmark)

Nikiforov, Aleksey; Tomás García, Antonio Luis; Petrushina, Irina

2011-01-01

The need of higher energy efficiency in hydrogen production has promoted the research on improved catalysts for water electrolysis. In this work, a novel supported catalyst for oxygen evolution electrodes was prepared and characterized with different techniques. IrO2 supported on a SiC/Si composite...

Coastal Foredune Evolution, Part 2: Modeling Approaches for Meso-Scale Morphologic Evolution

Science.gov (United States)

2017-03-01

for Meso-Scale Morphologic Evolution by Margaret L. Palmsten1, Katherine L. Brodie2, and Nicholas J. Spore2 PURPOSE: This Coastal and Hydraulics ...managers because foredunes provide ecosystem services and can reduce storm damages to coastal infrastructure, both of which increase the resiliency...MS 2 U.S. Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory, Duck, NC ERDC/CHL CHETN-II-57 March 2017 2 models of

Editorial - Special Issue on the Ninth International Conference on Aeolian Research - ICAR IX (Coastal Dune Processes and Aeolian Transport)

Science.gov (United States)

da Silva, Graziela Miot

2018-04-01

This special issue combines some of the papers related to coastal dune processes and aeolian sediment transport that were presented at the Ninth International Conference on Aeolian Research - ICAR IX. The conference was held between 4 and 8 of July 2016 in Mildura, Australia, organized by the International Society for Aeolian Research (ISAR) and convened by Adrian Chappell (Cardiff University), Craig Strong (Australian National University), Stephen Cattle (University of Sydney), Patrick Hesp (Flinders University), John Leys (New South Wales Office of Environment and Heritage), Lynda Petherick (University of Wellington) and Nick Webb (USDA-ARS Jornada Experimental Range).

Climatology of the Iberia coastal low-level wind jet: weather research forecasting model high-resolution results

Directory of Open Access Journals (Sweden)

Pedro M. M. Soares

2013-01-01

Full Text Available Coastal low-level jets (CLLJ are a low-tropospheric wind feature driven by the pressure gradient produced by a sharp contrast between high temperatures over land and lower temperatures over the sea. This contrast between the cold ocean and the warm land in the summer is intensified by the impact of the coastal parallel winds on the ocean generating upwelling currents, sharpening the temperature gradient close to the coast and giving rise to strong baroclinic structures at the coast. During summertime, the Iberian Peninsula is often under the effect of the Azores High and of a thermal low pressure system inland, leading to a seasonal wind, in the west coast, called the Nortada (northerly wind. This study presents a regional climatology of the CLLJ off the west coast of the Iberian Peninsula, based on a 9 km resolution downscaling dataset, produced using the Weather Research and Forecasting (WRF mesoscale model, forced by 19 years of ERA-Interim reanalysis (1989–2007. The simulation results show that the jet hourly frequency of occurrence in the summer is above 30% and decreases to about 10% during spring and autumn. The monthly frequencies of occurrence can reach higher values, around 40% in summer months, and reveal large inter-annual variability in all three seasons. In the summer, at a daily base, the CLLJ is present in almost 70% of the days. The CLLJ wind direction is mostly from north-northeasterly and occurs more persistently in three areas where the interaction of the jet flow with local capes and headlands is more pronounced. The coastal jets in this area occur at heights between 300 and 400 m, and its speed has a mean around 15 m/s, reaching maximum speeds of 25 m/s.

Trans-Disciplinary Education for Sustainable Marine and Coastal Management: A Case Study in Taiwan

Directory of Open Access Journals (Sweden)

Hsiao-Chien Lee

2016-10-01

Full Text Available The present study aims to investigate the effect of a trans-disciplinary design of curricula, deemed a powerful tool for teaching and research on complex environmental problems, with a goal to help solve the real problems that climate change has brought to the coastal environment in Taiwan. Three major real-life problems in southern Taiwan—declining mullet fisheries, flooding, and coral bleaching—were integrated into four courses. Adopting a qualitative case study method, the researchers investigated the student perceptions of the trans-disciplinary learning experiences, their attitudes toward marine and coastal environmental protection, and their capability of solving the problems related to marine and coastal environments. The researchers employed various methods to analyze the student reflection reports, student self-evaluation forms, and the tape-recorded class meetings. The findings suggest the following: the trans-disciplinary curriculum stands to be an innovative yet indispensable design for coastal management education; such a curriculum benefits students by equipping them with essential knowledge and skills to succeed in future marine conservation; action learning for marine and coastal sustainability serves as the final goal of trans-disciplinary learning project; a trans-disciplinary case study on the design of curricula provides effective knowledge integration of marine and coastal sustainability.

Diffusion of tritiated water in coastal areas

International Nuclear Information System (INIS)

Fukuda, M.; Kasai, A.; Imai, T.; Amano, H.; Yanase, N.

1980-01-01

The diffusion of tritiated water discharged by Japan Atomic Energy Research Institute at shore line has been investigated. In continuous discharge, the concentration of tritiated water in samples taken at a point downstream fluctuates largely. To reveal the cause, dye diffusion experiments were made in the coastal area. The shapes of dye cloud were photographed by a remote-control camera suspended from a captive balloon as color pictures. The movement of dye is so complex that a three-dimensional model must be employed to assess the diffusion in coastal areas

Characterization Of AIMgSi As Structure Material Of Research Reactor

International Nuclear Information System (INIS)

Sigit; Nuraini, E.

1998-01-01

Characterization of mechanical characteristic especially hardness, density and microstructure of aluminium alloy, AIMgSi, after heating processes at the temperature of 58-500 o C and heating time between 3-12 hours following by three cooling processes of different cooling rate I.e. : water quenching, cooling in air or in sands has been carried out. The hardness, density and microstructure than were determined. The experiments showed that the heating up to 300 o C for the three cooling process caused the decreasing al AIMgSi hardness from 76.2 kg/mm 2 to 34.4 kg/mm 2 , 34 kg/mm 2 dan 33.7 kg/mm 2 respectively for 3 hours heating, to 32.9 kg/mm 2 , 32.5 kg/mm 2 dan 31.8 kg/mm 2 respectively for 6 hours heating and to 34.4 kg/mm 2 , 33.1 kg/mm 2 dan 31.1 kg/mm 2 respectively for 12 hours heating. The heating caused also the change of AIMgSi of microstructure. At the heating of 85 o C to 300 o C the grains coarse from 0.225 mm to 0.24 mm, while at 500 o C the grains size were 0.18 mm. Heat treatment and cooling process which were carried out give no significant change of AIMgSi density

Geomorphic Regionalization of Coastal Zone Using Geospatial Technology

Directory of Open Access Journals (Sweden)

Manoranjan Mishra

2016-08-01

Full Text Available The world coastal environment is made of diversified landforms and are also potentially vulnerable to climate variability, delta sinking, extreme events and anthropogenic interferences. Sustainable management of coastal resources and transforming quality ecosystem services to future generation are the goals of Integrated Coastal Zone Management (ICZM. Geographical homogenous unit are the basic implementation locus and back bone of these kinds of integrated management strategy and activities. However, coastal zone management projects in developing world using use arbitrary land-ward and sea-ward boundaries from physical reference as unit of management. The oversimplified fixed distance approaches are not able to map the spatial and temporal changes in coastal systems. The spatio-temporal variations of coastal systems are configured in geomorphic landforms and further that work on interaction between natural forces and anthropogenic inputs. The present research work is an attempt to present a simplified method of regionalization geomorphic landforms using geospatial platforms for delineating Orissa coast into smaller homogenous geographic unit as reference point for future management. Geomorphic landforms are reconstructed using Enhanced Thematic Mapper Plus (ETM+ imagery, Survey of India topomaps, field survey and Digital Elevation Model data at geographic information system (GIS plat form. Seventy geomorphic features covering an area of 5033.64 km2 were identified and further, regionalized into five homogenous geographic units. The need of time is to recognize unsustainable coastal systems in these homogenous geographic units by fine tuning development parameters and also same time allowing coastal systems to adapt naturally to any kind of variability. Although, the methodology applied to Orissa for delineation homogenous geographic area but it can be replicated to any coast in world.

Hurricane Gustav: Observations and Analysis of Coastal Change

Science.gov (United States)

Doran, Kara S.; Stockdon, Hilary F.; Plant, Nathaniel G.; Sallenger, Asbury H.; Guy, Kristy K.; Serafin, Katherine A.

2009-01-01

Understanding storm-induced coastal change and forecasting these changes require knowledge of the physical processes associated with a storm and the geomorphology of the impacted coastline. The primary physical processes of interest are the wind field, storm surge, currents, and wave field. Not only does wind cause direct damage to structures along the coast, but it is ultimately responsible for much of the energy that is transferred to the ocean and expressed as storm surge, mean currents, and surface waves. Waves and currents are the processes most responsible for moving sediments in the coastal zone during extreme storm events. Storm surge, which is the rise in water level due to the wind, barometric pressure, and other factors, allows both waves and currents to attack parts of the coast not normally exposed to these processes. Coastal geomorphology, including shapes of the shoreline, beaches, and dunes, is also a significant aspect of the coastal change observed during extreme storms. Relevant geomorphic variables include sand dune elevation, beach width, shoreline position, sediment grain size, and foreshore beach slope. These variables, in addition to hydrodynamic processes, can be used to predict coastal vulnerability to storms. The U.S. Geological Survey (USGS) National Assessment of Coastal Change Hazards project (http://coastal.er.usgs.gov/hurricanes) strives to provide hazard information to those concerned about the Nation's coastlines, including residents of coastal areas, government agencies responsible for coastal management, and coastal researchers. As part of the National Assessment, observations were collected to measure morphological changes associated with Hurricane Gustav, which made landfall near Cocodrie, Louisiana, on September 1, 2008. Methods of observation included oblique aerial photography, airborne topographic surveys, and ground-based topographic surveys. This report documents these data-collection efforts and presents qualitative and

Study of Si/Si, Si/SiO2, and metal-oxide-semiconductor (MOS) using positrons

International Nuclear Information System (INIS)

Leung, To Chi.

1991-01-01

A variable-energy positron beam is used to study Si/Si, Si/SiO 2 , and metal-oxide-semiconductor (MOS) structures. The capability of depth resolution and the remarkable sensitivity to defects have made the positron annihilation technique a unique tool in detecting open-volume defects in the newly innovated low temperature (300C) molecular-beam-epitaxy (MBE) Si/Si. These two features of the positron beam have further shown its potential role in the study of the Si/SiO 2 . Distinct annihilation characteristics has been observed at the interface and has been studied as a function of the sample growth conditions, annealing (in vacuum), and hydrogen exposure. The MOS structure provides an effective way to study the electrical properties of the Si/SiO 2 interface as a function of applied bias voltage. The annihilation characteristics show a large change as the device condition is changed from accumulation to inversion. The effect of forming gas (FG) anneal is studied using positron annihilation and the result is compared with capacitance-voltage (C-V) measurements. The reduction in the number of interface states is found correlated with the changes in the positron spectra. The present study shows the importance of the positron annihilation technique as a non-contact, non-destructive, and depth-sensitive characterization tool to study the Si-related systems, in particular, the Si/SiO 2 interface which is of crucial importance in semiconductor technology, and fundamental understanding of the defects responsible for degradation of the electrical properties

Elevated Temperature Properties of Commercially Available NITE-SiC/SiC Composites

International Nuclear Information System (INIS)

Choi, Y.B.; Hinoki, T.; Kohyama, A.

2007-01-01

Full text of publication follows: Continuous fiber-reinforced ceramic matrix composites (CMCs) have been expected as a new type of material having high fracture resistance up to a high temperature. In recent years, there have been extensive efforts in our research group to develop high performance SiC/SiC composites for energy applications, where improvements in mechanical properties and damage resistance by innovative new fabrication process with emphasis on interface improvement have been greatly accomplished. One of the most outstanding accomplishments is the Nano-powder Infiltration and Transient Eutectic (NITE) process using PyC coated Tyranno-SA fibers. For making SiC/SiC composites more attractive and competitive for high temperature structural components and for other industrial applications, one of the key issues is to demonstrate its reliability and safety under severe environments. Also to demonstrate the potential to produce SiC/SiC by NITE process from large scale production line at industries is very important. This paper provides fundamental database of mechanical properties and microstructure of Cera-NITE, the trade name of NITE-SiC/SiC composites. The mechanical properties were evaluated by uni-axial tensile test from room temperature to high temperatures. The tensile properties, including elastic modulus, PLS and ultimate tensile strength, are superior to those of other conventional SiC/SiC composites. The macroscopic observation of Cera-NITE indicated high density as planned with almost no-porosity and cracks. Furthermore, Cera-NITE showed outstanding microstructural uniformity. The characteristic variation coming from the sampling location was hardly observed.. Further information about database of properties and microstructure at evaluated temperature will be provided. (authors)

Floristic Quality Index of Restored Wetlands in Coastal Louisiana

Science.gov (United States)

2017-08-01

ER D C/ EL T R- 17 -1 5 Ecosystem Management and Restoration Research Program Floristic Quality Index of Restored Wetlands in Coastal...of Wisconsin Lake Plant Communities with Example Applications. Lake and Reservoir Management 15(2): 133-141. Rocchio, J. 2007. Floristic Quality ... quality in Ohio wetlands. Science of the Total Environment 551: (556-562). Steyer, G. D., and R. E. Stewart, Jr. 1992. Monitoring Program for Coastal

Policies for Reducing Coastal Risk on the East and Gulf Coasts

Science.gov (United States)

Glickson, D.; Johnson, S.

2014-12-01

Hurricane- and coastal storm-related economic losses have increased substantially over the past century, largely due to expanding population and development in susceptible coastal areas. Concurrent with this growth, the federal government has assumed an increasing proportion of the financial responsibility associated with U.S. coastal storms, which may discourage state and local governments from taking appropriate actions to reduce risk and enhance resilience. Strategies to manage coastal storm risks fall into two categories: reducing the probability of flooding or wave impact (such as seawalls, storm surge barriers, beach nourishment, dune building, restoration/expansion of oyster reefs, salt marshes, and mangroves) and reducing the number or vulnerability of people or structures (such as relocation, land-use planning, and elevating or floodproofing buildings). Over the past century, most coastal risk management programs have emphasized coastal armoring, while doing little to decrease development in harm's way. This National Research Council report calls for the development of a national vision for managing coastal risks that includes a long-term view, regional solutions, and recognition of all benefits. A national coastal risk assessment is needed to identify high priority areas. Benefit-cost analysis provides a reasonable framework to evaluate national investments in coastal risk reduction, if constrained by other important environmental, social, and life-safety factors. Extensive collaboration and additional policy changes will be necessary to move from a nation that is primarily reactive to coastal disasters to one that invests wisely in coastal risk reduction and builds resilience among coastal communities.

Photoluminescence of Er-doped Si-SiO2 and Al-Si-SiO2 sputtered thin films

International Nuclear Information System (INIS)

Rozo, C.; Fonseca, L.F.; Jaque, D.; Sole, J.Garcia

2008-01-01

Er-doped Si-SiO 2 and Al-Si-SiO 2 films have been deposited by rf-sputtering being annealed afterwards. Annealing behavior of the Er 3+ : 4 I 13/2 → 4 I 15/2 emission of Er-doped Si-SiO 2 yields a maximum intensity for annealing at 700-800 deg. C. 4 I 13/2 → 4 I 15/2 peak emission for Er-doped Al-Si-SiO 2 at 1525 nm is shifted from that for Er-doped Si-SiO 2 at 1530 nm and the bandwidth increases from 29 to 42 nm. 4 I 13/2 → 4 I 15/2 emission decays present a fast decaying component related to Er ions coupled to Si nanoparticles, defects, or other ions, and a slow decaying component related to isolated Er ions. Excitation wavelength dependence and excitation power dependence for the 4 I 13/2 → 4 I 15/2 emission correspond with energy transfer from Si nanoparticles. Populating of the 4 I 11/2 level in Er-doped Si-SiO 2 involves branching and energy transfer upconversion involving two or more Er ions. Addition of Al reduces the populating of this level to an energy transfer upconversion involving two ions

COASTAL DYNAMICS OF SINGKAWANG, WEST KALIMANTAN

Directory of Open Access Journals (Sweden)

Yudi Darlan

2017-07-01

Full Text Available Morphologically, Singkawang and adjacent area consist of zones beaches, undulating hills, and steep hills. Granitic rocks and alluvium as a based rock of Singkawang coasts. Generally, Singkawang coasts was developed for coastal farms, fishery pond, and beach resorts, where most of these area have been eroded. Geological and physical oceanography condition are the aspects that build the characteristics of Singkawang coast. Human activities also play an important role in managing the equilibrium and dynamics of this coastal region. This research is to determine the dynamics and coastline changes of Singkawang coasts based on the characteristics of the coastal element and sediment. The high erosion was occurred at Semalagi–Cape Bajau. The Cape Bajau - Cape Banjar is relatively stable due to headlands of this coast is characterized by igneous rocks which resistant to the erosion. The Cape Banjar – South Coasts is very intensive erosion coast. Modern shorelines of the Singkawang coast might be as a shallow marine environment which were occurred thousands years ago (pre-Recent. The high of sedimentation process is generated by global sea level change, where was occurred at that time, and might be changed the area become part of the mainland coast of Singkawang. Keywords: coastal dynamics, erosion, sedimentation, Singkawang, West Kalimantan.

15 CFR 921.4 - Relationship to other provisions of the Coastal Zone Management Act, and to the Marine Protection...

Science.gov (United States)

2010-01-01

... the Coastal Zone Management Act, and to the Marine Protection, Research and Sanctuaries Act. 921.4... provisions of the Coastal Zone Management Act, and to the Marine Protection, Research and Sanctuaries Act. (a... affecting the state's coastal zone, must be undertaken in a manner consistent to the maximum extent...

A systems approach framework for coastal zones

DEFF Research Database (Denmark)

Hopkins, Tom Sawyer; Bailly, Denis; Støttrup, Josianne

2011-01-01

This Special Feature Volume examines the potential value of the Systems Approach Framework (SAF) as a methodological framework for the transition to sustainable development in coastal zones. This article provides insight on the Systems Approach, the theory behind it, and how its practical...... application to coastal zone systems (CZSs) was developed. The SAF is about information for management through a focus on how to generate a higher, dynamic level of information about complex CZSs and how to render this information more useful to end users through a participatory suite of communication methods....... The SAF is an open research methodology that investigates the function of systems in order to simulate specific issues or questions concerning their function. The research articles that are included in this Volume demonstrate examples of coupled multidisciplinary methods integrated into SAF simulations...

Coastal tourism, environment, and sustainable local development

Digital Repository Service at National Institute of Oceanography (India)

Noronha, L.; Lourenco, N.; Lobo-Ferreira, J.P.; Lieopart, A.; Feoli, E.; Sawkar, K.; Chachadi, A.

This book is among the products of a research project entitled "Measuring, monitoring and managing sustainability: The coastal dimension" INCO-DC programme over the period 1998-2002. The contributions reflect a range of disciplines including...

Radiation effects and micromechanics of SiC/SiC composites

International Nuclear Information System (INIS)

Ghoniem, N.M.

1992-01-01

The basic displacement damage process in SiC has been fully explored, and the mechanisms identified. Major modifications have been made to the theory of damage dosimetry in Fusion, Fission and Ion Simulation studies of Sic. For the first time, calculations of displacements per atoms in SiC can be made in any irradiation environment. Applications to irradiations in fusion first wall neutron spectra (ARIES and PROMETHEUS) as well as in fission spectra (HIFIR and FFTF) are given. Nucleation of helium-filled cavities in SiC was studied, using concepts of stability theory to determine the size of the critical nucleus under continuous generation of helium and displacement damage. It is predicted that a bimodal distribution of cavity sizes is likely to occur in heavily irradiated SiC. A study of the chemical compatibility of SiC composite structures with fusion reactor coolants at high-temperatures was undertaken. It was shown that SiC itself is chemically very stable in helium coolants in the temperature range 500--1000 degree C. However, current fiber/matrix interfaces, such as C and BN are not. The fracture mechanics of high-temperature matrix cracks with bridging fibers is now in progress. A fundamentally unique approach to study the propagation and interaction of cracks in a composite was initiated. The main focus of our research during the following period will be : (1) Theory and experiments for the micro-mechanics of high-temperature failure; and (2) Analysis of radiation damage and microstructure evolution

Land-based sources of marine pollution: Pesticides, PAHs and phthalates in coastal stream water, and heavy metals in coastal stream sediments in American Samoa

International Nuclear Information System (INIS)

Polidoro, Beth A.; Comeros-Raynal, Mia T.; Cahill, Thomas; Clement, Cassandra

2017-01-01

The island nations and territories of the South Pacific are facing a number of pressing environmental concerns, including solid waste management and coastal pollution. Here we provide baseline information on the presence and concentration of heavy metals and selected organic contaminants (pesticides, PAHs, phthalates) in 7 coastal streams and in surface waters adjacent to the Futiga landfill in American Samoa. All sampled stream sediments contained high concentrations of lead, and some of mercury. Several coastal stream waters showed relatively high concentrations of diethyl phthalate and of organophosphate pesticides, above chronic toxicity values for fish and other aquatic organisms. Parathion, which has been banned by the US Environmental Protection Agency since 2006, was detected in several stream sites. Increased monitoring and initiatives to limit non-point source land-based pollution will greatly improve the state of freshwater and coastal resources, as well as reduce risks to human health in American Samoa. - Highlights: • Several coastal stream sediments in American Samoa are high in lead and mercury. • Organophosphate pesticides, including Parathion, are present in coastal streams. • More research is needed on the sources, fate and impacts of these contaminants.

Essential coastal habitats for fish in the Baltic Sea

Science.gov (United States)

Kraufvelin, Patrik; Pekcan-Hekim, Zeynep; Bergström, Ulf; Florin, Ann-Britt; Lehikoinen, Annukka; Mattila, Johanna; Arula, Timo; Briekmane, Laura; Brown, Elliot John; Celmer, Zuzanna; Dainys, Justas; Jokinen, Henri; Kääriä, Petra; Kallasvuo, Meri; Lappalainen, Antti; Lozys, Linas; Möller, Peter; Orio, Alessandro; Rohtla, Mehis; Saks, Lauri; Snickars, Martin; Støttrup, Josianne; Sundblad, Göran; Taal, Imre; Ustups, Didzis; Verliin, Aare; Vetemaa, Markus; Winkler, Helmut; Wozniczka, Adam; Olsson, Jens

2018-05-01

Many coastal and offshore fish species are highly dependent on specific habitat types for population maintenance. In the Baltic Sea, shallow productive habitats in the coastal zone such as wetlands, vegetated flads/lagoons and sheltered bays as well as more exposed rocky and sandy areas are utilized by fish across many life history stages including spawning, juvenile development, feeding and migration. Although there is general consensus about the critical importance of these essential fish habitats (EFH) for fish production along the coast, direct quantitative evidence for their specific roles in population growth and maintenance is still scarce. Nevertheless, for some coastal species, indirect evidence exists, and in many cases, sufficient data are also available to carry out further quantitative analyses. As coastal EFH in the Baltic Sea are often found in areas that are highly utilized and valued by humans, they are subjected to many different pressures. While cumulative pressures, such as eutrophication, coastal construction and development, climate change, invasive species and fisheries, impact fish in coastal areas, the conservation coverage for EFH in these areas remains poor. This is mainly due to the fact that historically, fisheries management and nature conservation are not integrated neither in research nor in management in Baltic Sea countries. Setting joint objectives for fisheries management and nature conservation would hence be pivotal for improved protection of EFH in the Baltic Sea. To properly inform management, improvements in the development of monitoring strategies and mapping methodology for EFH are also needed. Stronger international cooperation between Baltic Sea states will facilitate improved management outcomes across ecologically arbitrary boundaries. This is especially important for successful implementation of international agreements and legislative directives such as the Baltic Sea Action Plan, the Marine Strategy Framework

β-FeSi2 films prepared on 6H-SiC substrates by magnetron sputtering

Science.gov (United States)

Hong, Li; Hongbin, Pu; Chunlei, Zheng; Zhiming, Chen

2015-06-01

β-FeSi2 thin films have been successfully prepared by magnetron sputtering and post rapid thermal annealing method on 6H-SiC (0001) substrates using a FeSi2 target and a Si target. X-ray diffraction (XRD) and Raman spectroscopy are applied to analyze the formation of β-FeSi2 films. XRD spectra reveal that the amorphous FeSi2 films are transformed to β-FeSi2 phase as the annealing temperature is increased from 500 to 900 °C for 5 min and the optimal annealing temperature is 900 °C. The formation of β-FeSi2 is also confirmed by Raman spectroscopy. Scanning electron microscope (SEM) observations indicate that the film is flat, relatively compact and the interface between β-FeSi2 and 6H-SiC is clear. Atomic force microscope (AFM) measurements demonstrate that the surface roughness confirmed by the root mean square (RMS) of the β-FeSi2 film is 0.87 nm. Near-infrared spectrophotometer observation shows that the absorption coefficient is of the order of 105 cm-1 and the optical band-gap of the β-FeSi2 film is 0.88 eV. The β-FeSi2 film with high crystal quality is fabricated by co-sputtering a FeSi2 target and a Si target for 60 min and annealing at 900 °C for 5 min. Project supported by the National Natural Science Foundation of China (No. 51177134) and the Natural Science Basic Research Plan in Shaanxi Province of China (No. 2015JM6286).

Examination of U3Si2-Al fuel elements from the Oak Ridge Research Reactor

International Nuclear Information System (INIS)

Copeland, G.L.; Snelgrove, J.L.; Hofman, G.L.

1986-01-01

The results of postirradiation examination of low-enriched U 3 Si 2 fuel elements from the Oak Ridge Research Reactor are presented. The elements replaced standard high-enriched elements and were handled routinely except that the burnup of half the elements was extended beyond normal limits up to about 98% peak. The elements were manufactured by commercial fuel suppliers. The performance was completely satisfactory for all the elements

Coastal Analysis, Nassau,NY

Data.gov (United States)

Federal Emergency Management Agency, Department of Homeland Security — Coastal study as defined in FEMA Guides and Specifications, Appendix D: Guidance for coastal Flooding Analyses and Mapping submitted as a result of a coastal study....

Coastal Adaptation: The Case of Ocean Beach, San Francisco

Science.gov (United States)

Cheong, S.

2012-12-01

stimuli in coastal adaptation initiatives and resulted in the Ocean Beach Master Plan. Investigation into the planning processes involving multiple stakeholder engagement such as San Francisco (SF) Public Utilities Commission, California Coastal Commission, National Park Service, SF Department of Public Works, SF Recreation and Park Department, SF Planning Department, and the U.S. Army Corps of Engineers can shed light on trade-offs and synergies of different adaptation responses. The role of the coordinator - SF Planning and Urban Research Commission - as a mediator between different stakeholder interests and priorities, a realistic assessment of current hazard management practices specific to local contexts, and the necessity of combining hazard mitigation policies with coastal management and community management are the key findings of this research. They help inform policy formulation and decision-making in climate change adaptation, and provide a valuable case study that can be transferred to other locations.

Coastal Dynamics

NARCIS (Netherlands)

Roelvink, J.A.; Steetzel, H.J.; Bliek, A.; Rakhorst, H.D.; Roelse, P.; Bakker, W.T.

1998-01-01

This book deals on "Coastal Dynamics", which will be defined in a narrow sense as a mathematical theory, which starts from given equations of motion for the sediment, which leads with the continuity equation and given boundary conditions to a calculated (eventually schematized) coastal topography,

Between a rock and a hard place: Environmental and engineering considerations when designing coastal defence structures

NARCIS (Netherlands)

Firth, L.B.; Thompson, R.C.; Bohn, K.; Abbiati, M.; Airoldi, L.; Bouma, T.J.; Bozzeda, F.; Ceccherelli, V.U.; Colangelo, M.A.; Evans, A.; Ferrario, F.; Hanley, M.E.; Hinz, H.; Hoggart, S.P.G.; Jackson, J.E.; Moore, P.; Morgan, E.H.; Perkol-Finkel, S.; Skov, M.W.; Strain, E.M.; van Belzen, J.; Hawkins, S.J.

2014-01-01

Coastal defence structures are proliferating as a result of rising sea levels and stormier seas. With the realisation that most coastal infrastructure cannot be lost or removed, research is required into ways that coastal defence structures can be built to meet engineering requirements, whilst also

Preliminary assessment of coastal erosion and local community adaptation in Sayung coastal area, central Java – Indonesia

OpenAIRE

Marfai, Muh Aris

2012-01-01

Dynamic environment in coastal area, especially due to coastal erosion process, has negative impact on human environment. Sayung coastal area, located in Central Java-Indonesia, has experienced severe impact of coastal erosion. As the result of the coastal erosion, hundreds of settlement located in coastal area has been destructed. Moreover, fishponds as the land use dominated in the coastal area also has been severely destroyed. Besides the coastal erosion, increasing of inundated area due t...

Southern African Coastal vulnerability assessment

CSIR Research Space (South Africa)

Rautenbach, C

2015-10-01

Full Text Available or business. The CSIR coastal systems group uses specialist skills in coastal engineering, geographic engineering systems and numerical modelling to assess and map vulnerable coastal ecosystems to develop specific adaptation measures and coastal protection...

Joining of thin thickness SiCf/SiC composites: research of a joining composition and of an associated elaboration process

International Nuclear Information System (INIS)

Jacques, E.

2012-01-01

The present work is part of the Fourth Generation Fast Reactors program. One of the key issues is the joining of the SiC f /SiC ceramic matrix composites (CMC) to seal the combustible cladding. At the present time, no chemical composition as a joint is refractive enough to face the expected operating temperatures. The aims of this study are the following: (1) the identification of a joining composition and its associated elaboration process answering the specifications, (2) the validation of a local and fast heating process and (3) the definition of mechanical tests to characterise these joinings. We describe the methodology and the results for joining SiC and SiC f /SiC substrates at solid and liquid state using metallic silicides. Joint integrity and joint strength can be improved by adding small SiC particles to the silicides powders. Chemical reactivity, wettability tests and thermomechanical properties analysis have been carried out on the joints. Cross sections of the assembly were prepared to study the joint/substrate chemical bonding, the cracking and the crack deflection in the vicinity of the interface. Also, one of the challenge consists in using a local heating at a high temperature (around 1800 C) for a short time to avoid the degradation of the composite structure. The assemblies have been then performed in an inductive furnace but in order to prepare the joining technology, trials of local heating have also been investigated with a CO 2 laser beam and a microwave generator. Finally, descriptions of the 4-points bending mechanical test used and the associated results are presented. (author) [fr

The Coastal Ocean Prediction Systems program: Understanding and managing our coastal ocean

International Nuclear Information System (INIS)

Eden, H.F.; Mooers, C.N.K.

1990-06-01

The goal of COPS is to couple a program of regular observations to numerical models, through techniques of data assimilation, in order to provide a predictive capability for the US coastal ocean including the Great Lakes, estuaries, and the entire Exclusive Economic Zone (EEZ). The objectives of the program include: determining the predictability of the coastal ocean and the processes that govern the predictability; developing efficient prediction systems for the coastal ocean based on the assimilation of real-time observations into numerical models; and coupling the predictive systems for the physical behavior of the coastal ocean to predictive systems for biological, chemical, and geological processes to achieve an interdisciplinary capability. COPS will provide the basis for effective monitoring and prediction of coastal ocean conditions by optimizing the use of increased scientific understanding, improved observations, advanced computer models, and computer graphics to make the best possible estimates of sea level, currents, temperatures, salinities, and other properties of entire coastal regions

Resilience from coastal protection.

Science.gov (United States)

Ewing, Lesley C

2015-10-28

Coastal areas are important residential, commercial and industrial areas; but coastal hazards can pose significant threats to these areas. Shoreline/coastal protection elements, both built structures such as breakwaters, seawalls and revetments, as well as natural features such as beaches, reefs and wetlands, are regular features of a coastal community and are important for community safety and development. These protection structures provide a range of resilience to coastal communities. During and after disasters, they help to minimize damages and support recovery; during non-disaster times, the values from shoreline elements shift from the narrow focus on protection. Most coastal communities have limited land and resources and few can dedicate scarce resources solely for protection. Values from shore protection can and should expand to include environmental, economic and social/cultural values. This paper discusses the key aspects of shoreline protection that influence effective community resilience and protection from disasters. This paper also presents ways that the economic, environmental and social/cultural values of shore protection can be evaluated and quantified. It presents the Coastal Community Hazard Protection Resilience (CCHPR) Index for evaluating the resilience capacity to coastal communities from various protection schemes and demonstrates the use of this Index for an urban beach in San Francisco, CA, USA. © 2015 The Author(s).

Development of the external cooling device of increase the productivity of neutron-transmutation-doped silicon semiconductor (NTD-Si) (Joint research)

International Nuclear Information System (INIS)

Hirose, Akira; Wada, Shigeru; Sasajima, Fumio; Kusunoki, Tsuyoshi; Kameyama, Iwao; Aizawa, Ryouji; Kikuchi, Naoyuki

2007-01-01

Neutron-Transmutation-Doped Silicon Semiconductor (hereinafter referred as 'NTD-Si') is the best semiconductor for the power device. The needs of NTD-Si increase recently in proportion to the popularization of hybrid-cars. A fission research reactor, which is a steady state neutron source, is being expected as the best device to meet the needs. So far, we have reconsidered the existing approach which is employed for NTD-Si production works at the research reactors JRR-3, JRR-4 and JMTR of JAEA so as to meet the needs. As one of the effective measures, we found out that the productivity can be increased by incorporating a new device to cool down radioactivity of irradiated silicon ingots at the place outside the main stream from the loading of silicon ingots to the withdrawal of irradiated ingots to the existing JRR-3 Uniformity Irradiation System. Consequently, we developed and installed the device (hereinafter referred as 'external cooling device'). After an ingot was irradiated once, it is turned over manually and irradiated again in order to irradiate the ingot uniformly. With the conventional system, it was necessary to wait the radioactivity of ingot decrease less than the permissible level with holding the ingot in the irradiation equipment. It was effective to shorten the waiting period by using an external cooling device for production increase of NTD-Si. It is expected that the productivity of NTD-Si will be increased by using the external cooling device. This report mentions the design of the external cooling device and verification between its design specifications and the performance of the device completed. (author)

Visualizing Our Options for Coastal Places: Exploring Realistic Immersive Geovisualizations as Tools for Inclusive Approaches to Coastal Planning and Management

Directory of Open Access Journals (Sweden)

Robert Newell

2017-09-01

Full Text Available Effective coastal planning is inclusive and incorporates the variety of user needs, values and interests associated with coastal environments. Realistic, immersive geographic visualizations, i.e., geovisualizations, can serve as potentially powerful tools for facilitating such planning because they can provide diverse groups with vivid understandings of how they would feel about certain management outcomes or impacts if transpired in real places. However, the majority of studies in this area have focused on terrestrial environments, and research on applications of such tools in the coastal and marine contexts is in its infancy. The current study aims to advance such research by examining the potential a land-to-sea geovisualization has to serve as a tool for inclusive coastal planning efforts. The research uses Sidney Spit Park (BC, Canada as a study site, and a realistic, dynamic geovisualization of the park was developed (using Unity3D that allows users to interact with and navigate it through the first-person perspective. Management scenarios were developed based on discussions with Parks Canada, and these scenarios included fencing around vegetation areas, positioning of mooring buoys, and management of dog activity within the park. Scenarios were built into the geovisualization in a manner that allows users to toggle different options. Focus groups were then assembled, involving residents of the Capital Regional District (BC, Canada, and participants explored and provided feedback on the scenarios. Findings from the study demonstrate the geovisualization's usefulness for assessing certain qualities of scenarios, such as aesthetics and functionality of fencing options and potential viewshed impacts associated with different mooring boat locations. In addition, the study found that incorporating navigability into the geovisualization proved to be valuable for understanding scenarios that hold implications for the marine environment due to

76 FR 39857 - Alaska Coastal Management Program Withdrawal From the National Coastal Management Program Under...

Science.gov (United States)

2011-07-07

... DEPARTMENT OF COMMERCE National Oceanic Atmospheric Administration Alaska Coastal Management Program Withdrawal From the National Coastal Management Program Under the Coastal Zone Management Act (CZMA) AGENCY: Office of Ocean and Coastal Resource Management (OCRM), National Ocean Service (NOS...

Research on ZnO/Si heterojunction solar cells

DEFF Research Database (Denmark)

Chen, Li; Chen, Xinliang; Liu, Yiming

2017-01-01

We put forward an n-ZnO/p-Si heterojunction solar cell model based on AFORS-HET simulations and provide experimental support in this article. ZnO: B (B-doped ZnO) thin films deposited by metal-organic chemical vapor deposition (MOCVD) are planned to act as electrical emitter layer on p-type c...

Formulating a coastal zone health metric for landuse impact management in urban coastal zones.

Science.gov (United States)

Anilkumar, P P; Varghese, Koshy; Ganesh, L S

2010-11-01

The need for ICZM arises often due to inadequate or inappropriate landuse planning practices and policies, especially in urban coastal zones which are more complex due to the larger number of components, their critical dimensions, attributes and interactions. A survey of literature shows that there is no holistic metric for assessing the impacts of landuse planning on the health of a coastal zone. Thus there is a need to define such a metric. The proposed metric, CHI (Coastal zone Health Indicator), developed on the basis of coastal system sustainability, attempts to gauge the health status of any coastal zone. It is formulated and modeled through an expert survey and pertains to the characteristic components of coastal zones, their critical dimensions, and relevant attributes. The proposed metric is applied to two urban coastal zones and validated. It can be used for more coast friendly and sustainable landuse planning/masterplan preparation and thereby for the better management of landuse impacts on coastal zones. Copyright 2010 Elsevier Ltd. All rights reserved.

Issues in ecology: Nutrient pollution of coastal rivers, bays, and seas

Science.gov (United States)

Howarth, Robert W.; Anderson, D. B.; Cloern, James E.; Elfring, Chris; Hopkinson, Charles S.; Lapointe, Brian; Maloney, Thomas J.; Marcus, Nancy; McGlathery, Karen; Sharpley, A.N.; Walker, D.

2000-01-01

Over the past 40 years, antipollution laws have greatly reduced discharges of toxic substances into our coastal waters. This effort, however, has focused largely on point-source pollution of industrial and municipal effluent. No comparable effort has been made to restrict the input of nitrogen (N) from municipal effluent, nor to control the flows of N and phosphorus (P) that enter waterways from dispersed or nonpoint sources such as agricultural and urban runoff or as airborne pollutants. As a result, inputs of nonpoint pollutants, particularly N, have increased dramatically. Nonpoint pollution from N and P now represents the largest pollution problem facing the vital coastal waters of the United States. Nutrient pollution is the common thread that links an array of problems along the nation’s coastline, including eutrophication, harmful algal blooms, ”dead zones,” fish kills, some shellfish poisonings, loss of seagrass and kelp beds, some coral reef destruction, and even some marine mammal and seabird deaths. More than 60 percent of our coastal rivers and bays in every coastal state of the continental United States are moderately to severely degraded by nutrient pollution. This degradation is particularly severe in the mid Atlantic states, in the southeast, and in the Gulf of Mexico. A recent report from the National Research Council entitled “Clean Coastal Waters: Understanding and Reduc- ing the Effects of Nutrient Pollution” concludes that: Nutrient over-enrichment of coastal ecosystems generally triggers ecological changes that decrease the biologi- cal diversity of bays and estuaries. While moderate N enrichment of some coastal waters may increase fish production, over-enrichment generally degrades the marine food web that supports commercially valuable fish. The marked increase in nutrient pollution of coastal waters has been accompanied by an increase in harmful algal blooms, and in at least some cases, pollution has triggered these blooms. High

Characterization of Si(112) and In/Si(112) studied by SPA-LEED

Energy Technology Data Exchange (ETDEWEB)

Hoecker, Jan; Speckmann, Moritz; Schmidt, Thomas; Falta, Jens [Institute of Solid State Physics, University of Bremen, 28359 Bremen (Germany)

2010-07-01

High index surfaces are of strong interest in todays research because of the possibility to grow low dimensional structures. It has for instance already been shown that the adsorption of Ga can induce the formation of 1D metal chains on Si(112) (cf. Snijders et al., PRB 72, 2005). In this work we investigated the clean Si(112) surface and the adsorption of In on Si(112) to establish an analogy to Ga/Si(112) using spot profile analyzing low energy electron diffraction (SPA-LEED). By means of reciprocal space mapping we determined the bare Si(112) surface to be decomposed into alternating (5512) and (111) facets in [1 anti 10] direction with (2 x 1) and (7 x 7) reconstruction, respectively (cf. Baski et al., Surf. Sci. 392, 1997). With SPA-LEED we were able to observe the decreasing intensity of the facet spots in-situ while depositing In on Si(112) and thus reveal the smoothening of the surface due to the deposition of In. At saturation coverage we found a (3.x1) reconstruction, where x is dependent on the deposition temperature and changes from x=7 at 400 C to x=5 at 500 C. This leads us to the assumption that the reconstruction is not incommensurate but a mixture of (3 x 1) and (4 x 1) building blocks, which is very similar to the super structure of Ga on Si(112).

Electronic states at Si-SiO2 interface introduced by implantation of Si in thermal SiO2

International Nuclear Information System (INIS)

Kalnitsky, A.; Poindexter, E.H.; Caplan, P.J.

1990-01-01

Interface traps due to excess Si introduced into the Si-SiO 2 system by ion implantation are investigated. Implanted oxides are shown to have interface traps at or slightly above the Si conduction band edge with densities proportional to the density of off-stoichiometric Si at the Si-SiO 2 interface. Diluted oxygen annealing is shown to result in physical separation of interface traps and equilibrium substrate electrons, demonstrating that ''interface'' states are located within a 0.5 nm thick layer of SiO 2 . Possible charge trapping mechanisms are discussed and the effect of these traps on MOS transistor characteristics is described using a sheet charge model. (author)

The effect of SiC particle size on the properties of Cu–SiC composites

International Nuclear Information System (INIS)

Celebi Efe, G.; Zeytin, S.; Bindal, C.

2012-01-01

Graphical abstract: The relative densities of Cu–SiC composites sintered at 700 °C for 2 h are ranged from 97.3% to 91.8% for SiC with 1 μm particle size and 97.5% to 95.2% for SiC with 5 μm particle size, microhardness of composites ranged from 143 to 167 HV for SiC having 1 μm particle size and 156–182 HVN for SiC having 5 μm particle size and the electrical conductivity of composites changed between 85.9% IACS and 55.7% IACS for SiC with 1 μm particle size, 87.9% IACS and 65.2%IACS for SiC with 5 μm particle size. It was found that electrical conductivity of composites containing SiC with 5 μm particle size is better than that of Cu–SiC composites containing SiC with particle size of 1 μm. Highlights: ► In this research, the effect of SiC particle size on some properties of Cu–SiC composites were investigated. ► The mechanical properties were improved. ► The electrical properties were obtained at desirable level. -- Abstract: SiC particulate-reinforced copper composites were prepared by powder metallurgy (PM) method and conventional atmospheric sintering. Scanning electron microscope (SEM), X-ray diffraction (XRD) techniques were used to characterize the sintered composites. The effect of SiC content and particle size on the relative density, hardness and electrical conductivity of composites were investigated. The relative densities of Cu–SiC composites sintered at 700 °C for 2 h are ranged from 97.3% to 91.8% for SiC with 1 μm particle size and from 97.5% to 95.2% for SiC with 5 μm particle size. Microhardness of composites ranged from 143 to 167 HV for SiC having 1 μm particle size and from 156 to 182 HV for SiC having 5 μm particle size. The electrical conductivity of composites changed between 85.9% IACS and 55.7% IACS for SiC with 1 μm particle size, between 87.9% IACS and 65.2% IACS for SiC with 5 μm particle size.

Impacts of Coastal Inundation Due to Climate Change in a CLUSTER of Urban Coastal Communities in Ghana, West Africa

Directory of Open Access Journals (Sweden)

Patrick Kwabena Ofori-Danson

2011-09-01

Full Text Available The increasing rates of sea level rise caused by global warming within the 21st century are expected to exacerbate inundation and episodic flooding tide in low-lying coastal environments. This development threatens both human development and natural habitats within such coastal communities. The impact of sea level rise will be more pronounced in developing countries where there is limited adaptation capacity. This paper presents a comprehensive assessment of the expected impacts of sea level rise in three communities in the Dansoman coastal area of Accra, Ghana. Future sea level rises were projected based on global scenarios and the Commonwealth Scientific and Industrial Research Organization General Circulation Models—CSIRO_MK2_GS GCM. These were used in the SimCLIM model based on the modified Bruun rule and the simulated results overlaid on near vertical aerial photographs taken in 2005. It emerged that the Dansoman coastline could recede by about 202 m by the year 2100 with baseline from 1970 to 1990. The potential impacts on the socioeconomic and natural systems of the Dansoman coastal area were characterized at the Panbros, Grefi and Gbegbeyise communities. The study revealed that about 84% of the local dwellers is aware of the rising sea level in the coastal area but have poor measures of adapting to the effects of flood disasters. Analysis of the likely impacts of coastal inundation revealed that about 650,000 people, 926 buildings and a total area of about 0.80 km2 of land are vulnerable to permanent inundation by the year 2100. The study has shown that there will be significant losses to both life and property by the year 2100 in the Dansoman coastal community in the event of sea level rise.

Nonvolatile field effect transistors based on protons and Si/SiO2Si structures

International Nuclear Information System (INIS)

Warren, W.L.; Vanheusden, K.; Fleetwood, D.M.; Schwank, J.R.; Winokur, P.S.; Knoll, M.G.; Devine, R.A.B.

1997-01-01

Recently, the authors have demonstrated that annealing Si/SiO 2 /Si structures in a hydrogen containing ambient introduces mobile H + ions into the buried SiO 2 layer. Changes in the H + spatial distribution within the SiO 2 layer were electrically monitored by current-voltage (I-V) measurements. The ability to directly probe reversible protonic motion in Si/SiO 2 /Si structures makes this an exemplar system to explore the physics and chemistry of hydrogen in the technologically relevant Si/SiO 2 structure. In this work, they illustrate that this effect can be used as the basis for a programmable nonvolatile field effect transistor (NVFET) memory that may compete with other Si-based memory devices. The power of this novel device is its simplicity; it is based upon standard Si/SiO 2 /Si technology and forming gas annealing, a common treatment used in integrated circuit processing. They also briefly discuss the effects of radiation on its retention properties

New fundamental defects in a-SiO2

International Nuclear Information System (INIS)

Karna, S.P.; Kurtz, H.A.; Shedd, W.M.; Pugh, R.D.; Singaraju, B.K.

1999-01-01

Throughout the three decades of research into radiation-induced degradation of metal-oxide-semiconductor (MOS) devices, investigators understood that point defects in the Si-SiO 2 structure (localized deviations from stoichiometrically pure Si and SiO 2 ) are responsible for many observed anomalies. Basic research in this area has progressed along two tracks: (i) differentiating the anomalies based upon subtle differences in their characteristic behavior, and (ii) precise description of the defects responsible for the anomalous behavior. These two research tracks are complementary since often a discovery in one area provides insight and ultimately leads to discoveries in the other. Here, the atomic structure and spin properties of two previously undescribed amorphous silicon dioxide fundamental point defects have been characterized for the first time by ab initio quantum mechanical calculations. Both defects are electrically neutral trivalent silicon centers in the oxide. One of the defects, the X-center, is determined to have an O 2 Sitriple b ondSi ↑ atomic structure. The other defect, called the Y-center, is found to have an OSi 2 triple b ondSi ↑ structure. Calculated electronic and electrical properties of the new defect centers are consistent with the published characteristics of the oxide switching trap or border trap precursors

Effects of dual-ion irradiation on the swelling of SiC/SiC composites

International Nuclear Information System (INIS)

Kishimoto, Hirotatsu; Kohyama, Akira; Ozawa, Kazumi; Kondo, Sosuke

2005-01-01

Silicon carbide (SiC) matrix composites reinforced by SiC fibers is a candidate structural material of fusion gas-cooled blanket system. From the viewpoint of material designs, it is important to investigate the swelling by irradiation, which results from the accumulation of displacement damages. In the fusion environment, (n, α) nuclear reactions are considered to produce helium gas in SiC. For the microstructural evolution, a dual-ion irradiation method is able to simulate the effects of helium. In the present research, 1.7 MeV tandem and 1 MeV single-end accelerators were used for Si self-ion irradiation and helium implantation, respectively. The average helium over displacement per atom (dpa) ratio in SiC was adjusted to 60 appm/dpa. The irradiation temperature ranged from room temperature to 1400degC. The irradiation-induced swelling was measured by the step height method. Helium that was implanted simultaneously with displacement damages in dual-ion irradiated SiC increased the swelling that was larger than that by single-ion irradiated SiC below 800degC. Since this increase was not observed above 1000degC, the interaction of helium and displacement damages was considered to change above 800degC. In this paper, the microstructural behavior and dimensional stability of SiC materials under the fusion relevant environment are discussed. (author)

A Global Estimate of Seafood Consumption by Coastal Indigenous Peoples.

Science.gov (United States)

Cisneros-Montemayor, Andrés M; Pauly, Daniel; Weatherdon, Lauren V; Ota, Yoshitaka

2016-01-01

Coastal Indigenous peoples rely on ocean resources and are highly vulnerable to ecosystem and economic change. Their challenges have been observed and recognized at local and regional scales, yet there are no global-scale analyses to inform international policies. We compile available data for over 1,900 coastal Indigenous communities around the world representing 27 million people across 87 countries. Based on available data at local and regional levels, we estimate a total global yearly seafood consumption of 2.1 million (1.5 million-2.8 million) metric tonnes by coastal Indigenous peoples, equal to around 2% of global yearly commercial fisheries catch. Results reflect the crucial role of seafood for these communities; on average, consumption per capita is 15 times higher than non-Indigenous country populations. These findings contribute to an urgently needed sense of scale to coastal Indigenous issues, and will hopefully prompt increased recognition and directed research regarding the marine knowledge and resource needs of Indigenous peoples. Marine resources are crucial to the continued existence of coastal Indigenous peoples, and their needs must be explicitly incorporated into management policies.

Coastal High-resolution Observations and Remote Sensing of Ecosystems (C-HORSE)

Science.gov (United States)

Guild, Liane

2016-01-01

Coastal benthic marine ecosystems, such as coral reefs, seagrass beds, and kelp forests are highly productive as well as ecologically and commercially important resources. These systems are vulnerable to degraded water quality due to coastal development, terrestrial run-off, and harmful algal blooms. Measurements of these features are important for understanding linkages with land-based sources of pollution and impacts to coastal ecosystems. Challenges for accurate remote sensing of coastal benthic (shallow water) ecosystems and water quality are complicated by atmospheric scattering/absorption (approximately 80+% of the signal), sun glint from the sea surface, and water column scattering (e.g., turbidity). Further, sensor challenges related to signal to noise (SNR) over optically dark targets as well as insufficient radiometric calibration thwart the value of coastal remotely-sensed data. Atmospheric correction of satellite and airborne remotely-sensed radiance data is crucial for deriving accurate water-leaving radiance in coastal waters. C-HORSE seeks to optimize coastal remote sensing measurements by using a novel airborne instrument suite that will bridge calibration, validation, and research capabilities of bio-optical measurements from the sea to the high altitude remote sensing platform. The primary goal of C-HORSE is to facilitate enhanced optical observations of coastal ecosystems using state of the art portable microradiometers with 19 targeted spectral channels and flight planning to optimize measurements further supporting current and future remote sensing missions.

External dose rates in coastal urban environments in Brazil

International Nuclear Information System (INIS)

Souza, E.M.; Rochedo, E.R.R.; Conti, C.C.

2015-01-01

A long term activity aiming on assessing the exposure of the Brazilian population to natural background radiation is being developed at IRD/CNEN. Several research groups within IRD work in this activity, although mostly as a parallel work associated to main research lines followed by researches of the institution. One main activity is related to the raise of external gamma dose rates throughout the country. The objective of this work is to present results from recent surveys performed as part of the emergency preparedness for radiological emergencies during major public events in Brazil, such as the the World Youth Day, held in Rio de Janeiro in 2013, and the Confederations Cup and the FIFA World Cup soccer games, in 2013 and 2014, respectively. In this work, only the recent (2014) coastal urban environments measurements were included. Average kerma rates for Fortaleza is 80 ± 23 nGy/h, for Vitoria is 96 ± 33 nGy/h and for Angra dos Reis is 147 ± 16 nGy/h. These results are then compared to previous results on other coastal urban towns (Rio de Janeiro, Niterói and Salvador), and with the high background coastal area of Guarapari town. (authors)

Gulf Atlantic Coastal Plain Long Term Agroecosystem Research site, Tifton, GA

Science.gov (United States)

Timothy Strickland; David D. Bosch; Dinku M. Endale; Thomas L. Potter

2016-01-01

The Gulf-Atlantic Coastal Plain (GACP) physiographic region is an important agricultural production area within the southeastern U.S. that extends from Delaware in the Northeast to the Gulf Coast of Texas. The region consists mainly of low-elevation flat to rolling terrain with numerous streams, abundant rainfall, a complex coastline, and many wetlands. The GACP Long ...

Spatial data quality and coastal spill modelling

International Nuclear Information System (INIS)

Li, Y.; Brimicombe, A.J.; Ralphs, M.P.

1998-01-01

Issues of spatial data quality are central to the whole oil spill modelling process. Both model and data quality performance issues should be considered as indispensable parts of a complete oil spill model specification and testing procedure. This paper presents initial results of research that will emphasise to modeler and manager alike the practical issues of spatial data quality for coastal oil spill modelling. It is centred around a case study of Jiao Zhou Bay in the People's Republic of China. The implications for coastal oil spill modelling are discussed and some strategies for managing the effects of spatial data quality in the outputs of oil spill modelling are explored. (author)

The change in the primary production of Danish coastal waters

International Nuclear Information System (INIS)

Edelvang, K.; Erichsen, A.; Gustavson, K.; Bundgaard, K.; Dahl-Madsen, K.I.

2001-01-01

The background for this study is the development of the 'Farvandsmodel' for the NOVA-2003 programme and the nationally founded research project DECO (Danish Environmental Monitoring of Coastal Waters), which focuses on the use of remote sensing for the monitoring of Danish Coastal waters. Danish national programmes for the monitoring of the marine ecosystem are a relatively new activity, which has grown during the last 20 years. The HAV90 research programme amassed important information to be included in future environmental efforts such as the NOVA-2003 programme, aimed at monitoring the Danish coastal waters. The following is a selection of the topics mentioned in the NOVA-2003 programme (NOVA-2003, 2000) especially relevant to this study: 1) Hydrography. 2) Concentration and spatial distribution of nutrients. 3) Water and nutrient fluxes. 4) Oxygen depletion. As part of this programme, a 3D hydrographic model describing currents and fluxes in Danish waters has been designed by DHI Water and Environment for the Danish Ministry of Energy and Environment. The model is called the 'Farvandsmodel', which is the collective Danish name of this regional 3D hydrodynamic model and its associated database for storage and dissemination of model results and field measurements. The model is planned to be in operation until 2004. It has a great potential within hydrographic modelling in Danish waters, as it is capable of running 5-day prognoses for currents, water levels and stratification. The model is also able to calculate the sensitivity of the present system to changes in various input parameters. In this way the model may be used as a tool for testing the sensitivity of Danish coastal waters to the impact of the green house effects. The nationally funded research programme, DECO (1997-2000), aims to investigate the use of remote sensing for monitoring Danish coastal waters. To support this research, a eutrophication module (EU) was set up for the 'Farvandsmodel'. The

Sub-barrier fusion of Si+Si systems

Science.gov (United States)

Colucci, G.; Montagnoli, G.; Stefanini, A. M.; Bourgin, D.; Čolović, P.; Corradi, L.; Courtin, S.; Faggian, M.; Fioretto, E.; Galtarossa, F.; Goasduff, A.; Haas, F.; Mazzocco, M.; Scarlassara, F.; Stefanini, C.; Strano, E.; Urbani, M.; Szilner, S.; Zhang, G. L.

2017-11-01

The near- and sub-barrier fusion excitation function has been measured for the system 30Si+30Si at the Laboratori Nazionali di Legnaro of INFN, using the 30Si beam of the XTU Tandem accelerator in the energy range 47 - 90 MeV. A set-up based on a beam electrostatic deflector was used for detecting fusion evaporation residues. The measured cross sections have been compared to previous data on 28Si+28Si and Coupled Channels (CC) calculations have been performed using M3Y+repulsion and Woods-Saxon potentials, where the lowlying 2+ and 3- excitations have been included. A weak imaginary potential was found to be necessary to reproduce the low energy 28Si+28Si data. This probably simulates the effect of the oblate deformation of this nucleus. On the contrary, 30Si is a spherical nucleus, 30Si+30Si is nicely fit by CC calculations and no imaginary potential is needed. For this system, no maximum shows up for the astrophysical S-factor so that we have no evidence for hindrance, as confirmed by the comparison with CC calculations. The logarithmic derivative of the two symmetric systems highlights their different low energy trend. A difference can also be noted in the two barrier distributions, where the high-energy peak present in 28Si+28Si is not observed for 30Si+30Si, probably due to the weaker couplings in last case.

Sub-barrier fusion of Si+Si systems

Directory of Open Access Journals (Sweden)

Colucci G.

2017-01-01

Full Text Available The near- and sub-barrier fusion excitation function has been measured for the system 30Si+30Si at the Laboratori Nazionali di Legnaro of INFN, using the 30Si beam of the XTU Tandem accelerator in the energy range 47 - 90 MeV. A set-up based on a beam electrostatic deflector was used for detecting fusion evaporation residues. The measured cross sections have been compared to previous data on 28Si+28Si and Coupled Channels (CC calculations have been performed using M3Y+repulsion and Woods-Saxon potentials, where the lowlying 2+ and 3− excitations have been included. A weak imaginary potential was found to be necessary to reproduce the low energy 28Si+28Si data. This probably simulates the effect of the oblate deformation of this nucleus. On the contrary, 30Si is a spherical nucleus, 30Si+30Si is nicely fit by CC calculations and no imaginary potential is needed. For this system, no maximum shows up for the astrophysical S-factor so that we have no evidence for hindrance, as confirmed by the comparison with CC calculations. The logarithmic derivative of the two symmetric systems highlights their different low energy trend. A difference can also be noted in the two barrier distributions, where the high-energy peak present in 28Si+28Si is not observed for 30Si+30Si, probably due to the weaker couplings in last case.

Nitric acid oxidation of Si (NAOS) method for low temperature fabrication of SiO{sub 2}/Si and SiO{sub 2}/SiC structures

Energy Technology Data Exchange (ETDEWEB)

Kobayashi, H., E-mail: koba771@ybb.ne.jp [Institute of Scientific and Industrial Research, Osaka University, and CREST, Japan Science and Technology Agency, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); Imamura, K.; Kim, W.-B.; Im, S.-S.; Asuha [Institute of Scientific and Industrial Research, Osaka University, and CREST, Japan Science and Technology Agency, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan)

2010-07-15

We have developed low temperature formation methods of SiO{sub 2}/Si and SiO{sub 2}/SiC structures by use of nitric acid, i.e., nitric acid oxidation of Si (or SiC) (NAOS) methods. By use of the azeotropic NAOS method (i.e., immersion in 68 wt% HNO{sub 3} aqueous solutions at 120 deg. C), an ultrathin (i.e., 1.3-1.4 nm) SiO{sub 2} layer with a low leakage current density can be formed on Si. The leakage current density can be further decreased by post-metallization anneal (PMA) at 200 deg. C in hydrogen atmosphere, and consequently the leakage current density at the gate bias voltage of 1 V becomes 1/4-1/20 of that of an ultrathin (i.e., 1.5 nm) thermal oxide layer usually formed at temperatures between 800 and 900 deg. C. The low leakage current density is attributable to (i) low interface state density, (ii) low SiO{sub 2} gap-state density, and (iii) high band discontinuity energy at the SiO{sub 2}/Si interface arising from the high atomic density of the NAOS SiO{sub 2} layer. For the formation of a relatively thick (i.e., {>=}10 nm) SiO{sub 2} layer, we have developed the two-step NAOS method in which the initial and subsequent oxidation is performed by immersion in {approx}40 wt% HNO{sub 3} and azeotropic HNO{sub 3} aqueous solutions, respectively. In this case, the SiO{sub 2} formation rate does not depend on the Si surface orientation. Using the two-step NAOS method, a uniform thickness SiO{sub 2} layer can be formed even on the rough surface of poly-crystalline Si thin films. The atomic density of the two-step NAOS SiO{sub 2} layer is slightly higher than that for thermal oxide. When PMA at 250 deg. C in hydrogen is performed on the two-step NAOS SiO{sub 2} layer, the current-voltage and capacitance-voltage characteristics become as good as those for thermal oxide formed at 900 deg. C. A relatively thick (i.e., {>=}10 nm) SiO{sub 2} layer can also be formed on SiC at 120 deg. C by use of the two-step NAOS method. With no treatment before the NAOS method

Evaluation of sustainable walk-up flats in terms of urban housing renewal in coastal area

Science.gov (United States)

Septanti, D.; Kisnarini, R.; Setyawan, W.; Utami, ASPR

2018-03-01

Urban housing renewal aims to get added value while maintaining the sustainability of its environmental function and quality [4]. This research discusses the urban renewal which is done by rebuilding the affected area with walk-up flats. There are four aspects to be considered in achieving sustainability, namely: environmental, social, economic, and cultural [14]. This study is focused on cultural aspect. Sustainable walk-up flats, viewed from the micro context perspective, can later be used as one of the terms of reference in assessing the success of urban renewal projects in Indonesia. Especially in coastal areas, it becomes more challenging because coastal communities have different characteristics and the existing urban renewal flats are not necessarily appropriate for the coastal community. The methods used in this study are explorative, descriptive, ex- post, cross-sectional and synchronic evaluation. This research describes the characteristics of citizens, activities at home and the environment. Thus, the conclusions which are drawn by deductive reasoning are done using frequency, mean, etc. A mixed research method is applied combining with the analysis of quantitative and qualitative data collection and interpretation, including determining quantitative indicators and space design attributes, and qualitative user needs. This research is located in Surabaya as a sample of coastal cities with urban and environmental problems. The results of this study are the findings of indicators, directions, and concepts for Sustainable Housing Development in Coastal Areas which further can be made as scientific recommendation (to support the Housing Theory and Urban Renewal) and contribute to practical guidelines for sustainable low-cost walk-up flats in coastal areas.

THE IMPLEMENTATION OF LILIFUK CUSTOMARY LAW TOWARDS COASTAL ENVIRONMENTAL DEGRADATION OF KUPANG BAY

Directory of Open Access Journals (Sweden)

Ranny Christine Unbanunaek

2017-02-01

Full Text Available The kuanheun coastal communities have a customary law that help maintain coastal environmental sustainability resourceS called as lilifuk customary law(lilifuk atolan instrument. This research applied empirical method by formulating three problems: what are the values embedded in lilifuk customary law; how is the of lilifuk customary law contribution to prevent coastal environmental degradation; and how is the correlation between lilifuk customary law values and the law provision on coastal areas and small islands management. The result of the research identified the following; the first, Lilifuk customary law contains religious value, ecological value, communal value, social relations value, solidarity and responsibility value, social leadership value, and educational value. Second, the settlement of law violation by lilifuk customary law is conduted by the following steps: reporting; discussion; verdict; and  execution. Third, there is a correlation between the lilifuk customary lilifuk values and  WP3K Law values. Keywords: lilifuk customary law, environmental degradation, kupang bay

Coastal defence and societal activities in the coastal zone: Compatible or conflicting interests?

NARCIS (Netherlands)

van Vuren, Saskia; Kok, Matthijs; Jorissen, Richard E.

2004-01-01

World-wide coastal zones are subject to physical and societal changes. Due to climate change sea level is expected to rise and storm conditions may become more intensive. Both may lead to shore erosion intensification in the coastal zone. Moreover, the coastal zone is intensely used for societal

Initial assessment of environmental effects on SiC/SiC composites in helium-cooled nuclear systems

Energy Technology Data Exchange (ETDEWEB)

Contescu, Cristian I [ORNL

2013-09-01

This report summarized the information available in the literature on the chemical reactivity of SiC/SiC composites and of their components in contact with the helium coolant used in HTGR, VHTR and GFR designs. In normal operation conditions, ultra-high purity helium will have chemically controlled impurities (water, oxygen, carbon dioxide, carbon monoxide, methane, hydrogen) that will create a slightly oxidizing gas environment. Little is known from direct experiments on the reactivity of third generation (nuclear grade) SiC/SiC composites in contact with low concentrations of water or oxygen in inert gas, at high temperature. However, there is ample information about the oxidation in dry and moist air of SiC/SiC composites at high temperatures. This information is reviewed first in the next chapters. The emphasis is places on the improvement in material oxidation, thermal, and mechanical properties during three stages of development of SiC fibers and at least two stages of development of the fiber/matrix interphase. The chemical stability of SiC/SiC composites in contact with oxygen or steam at temperatures that may develop in off-normal reactor conditions supports the conclusion that most advanced composites (also known as nuclear grade SiC/SiC composites) have the chemical resistance that would allow them maintain mechanical properties at temperatures up to 1200 1300 oC in the extreme conditions of an air or water ingress accident scenario. Further research is needed to assess the long-term stability of advanced SiC/SiC composites in inert gas (helium) in presence of very low concentrations (traces) of water and oxygen at the temperatures of normal operation of helium-cooled reactors. Another aspect that needs to be investigated is the effect of fast neutron irradiation on the oxidation stability of advanced SiC/SiC composites in normal operation conditions.

MECHANISMS FOR THE SEASONAL CYCLE IN THE ANTARCTIC COASTAL OCEANS

OpenAIRE

オオシマ; Kay I., OHSHIMA

1996-01-01

Seasonal variations of the Antarctic coastal oceans has not been well understood owing to logistical difficulties in observations, especially during the ice-covered season. Recently, 'Weddell Gyre Study' and 'Japanese Antarctic Climate Research program' have revealed the following seasonal variations in the Antarctic coastal ocean. First, the thickness of the Winter Water (WW) layer, characterized by cold, fresh, oxygen-rich water, exhibits its maximum in the austral fall and its minimum in t...

Coastal and Riverine Flood Forecast Model powered by ADCIRC

Science.gov (United States)

Khalid, A.; Ferreira, C.

2017-12-01

Coastal flooding is becoming a major threat to increased population in the coastal areas. To protect coastal communities from tropical storms & hurricane damages, early warning systems are being developed. These systems have the capability of real time flood forecasting to identify hazardous coastal areas and aid coastal communities in rescue operations. State of the art hydrodynamic models forced by atmospheric forcing have given modelers the ability to forecast storm surge, water levels and currents. This helps to identify the areas threatened by intense storms. Study on Chesapeake Bay area has gained national importance because of its combined riverine and coastal phenomenon, which leads to greater uncertainty in flood predictions. This study presents an automated flood forecast system developed by following Advanced Circulation (ADCIRC) Surge Guidance System (ASGS) guidelines and tailored to take in riverine and coastal boundary forcing, thus includes all the hydrodynamic processes to forecast total water in the Potomac River. As studies on tidal and riverine flow interaction are very scarce in number, our forecast system would be a scientific tool to examine such area and fill the gaps with precise prediction for Potomac River. Real-time observations from National Oceanic and Atmospheric Administration (NOAA) and field measurements have been used as model boundary feeding. The model performance has been validated by using major historical riverine and coastal flooding events. Hydrodynamic model ADCIRC produced promising predictions for flood inundation areas. As better forecasts can be achieved by using coupled models, this system is developed to take boundary conditions from Global WaveWatchIII for the research purposes. Wave and swell propagation will be fed through Global WavewatchIII model to take into account the effects of swells and currents. This automated forecast system is currently undergoing rigorous testing to include any missing parameters which

Evolution of Hierarchical Structure and Spatial Pattern of Coastal Cities in China – Based on the Data of Distribution of Marine-Related Enterprises

Directory of Open Access Journals (Sweden)

Wang Lili

2017-11-01

Full Text Available In this paper, a comprehensive research of the evolution of the hierarchical structure and spatial pattern of coastal cities in China was conducted based on the data of distribution of the headquarters and subsidiaries of marine-related enterprises in 1995, 2005 and 2015 using the city network research method proposed by Taylor. The results of the empirical research showed: China’s coastal city network had an obvious hierarchical characteristics of “national coastal cityregional coastal city-sub-regional coastal city-local coastal city”, in the 20 years of development process, the hierarchies of coastal cities in China showed a hierarchical progressive evolution; in past 20 years, the spatial pattern and network structure of coastal cities in China tended to be complete, and the city network was more uniform, forming a “three tiers and three urban agglomerations” network structure; the strength of connection among the cities was obviously strengthened, and the efficiency of urban spatial connection was improved overall.

Our evolving conceptual model of the coastal eutrophication problem

Science.gov (United States)

Cloern, James E.

2001-01-01

A primary focus of coastal science during the past 3 decades has been the question: How does anthropogenic nutrient enrichment cause change in the structure or function of nearshore coastal ecosystems? This theme of environmental science is recent, so our conceptual model of the coastal eutrophication problem continues to change rapidly. In this review, I suggest that the early (Phase I) conceptual model was strongly influenced by limnologists, who began intense study of lake eutrophication by the 1960s. The Phase I model emphasized changing nutrient input as a signal, and responses to that signal as increased phytoplankton biomass and primary production, decomposition of phytoplankton-derived organic matter, and enhanced depletion of oxygen from bottom waters. Coastal research in recent decades has identified key differences in the responses of lakes and coastal-estuarine ecosystems to nutrient enrichment. The contemporary (Phase II) conceptual model reflects those differences and includes explicit recognition of (1) system-specific attributes that act as a filter to modulate the responses to enrichment (leading to large differences among estuarine-coastal systems in their sensitivity to nutrient enrichment); and (2) a complex suite of direct and indirect responses including linked changes in: water transparency, distribution of vascular plants and biomass of macroalgae, sediment biogeochemistry and nutrient cycling, nutrient ratios and their regulation of phytoplankton community composition, frequency of toxic/harmful algal blooms, habitat quality for metazoans, reproduction/growth/survival of pelagic and benthic invertebrates, and subtle changes such as shifts in the seasonality of ecosystem functions. Each aspect of the Phase II model is illustrated here with examples from coastal ecosystems around the world. In the last section of this review I present one vision of the next (Phase III) stage in the evolution of our conceptual model, organized around 5

Technique development for modulus, microcracking, hermeticity, and coating evaluation capability characterization of SiC/SiC tubes

Energy Technology Data Exchange (ETDEWEB)

Hu, Xunxiang [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Ang, Caen K. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Singh, Gyanender P. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Katoh, Yutai [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)

2016-08-01

Driven by the need to enlarge the safety margins of nuclear fission reactors in accident scenarios, research and development of accident-tolerant fuel has become an important topic in the nuclear engineering and materials community. A continuous-fiber SiC/SiC composite is under consideration as a replacement for traditional zirconium alloy cladding owing to its high-temperature stability, chemical inertness, and exceptional irradiation resistance. An important task is the development of characterization techniques for SiC/SiC cladding, since traditional work using rectangular bars or disks cannot directly provide useful information on the properties of SiC/SiC composite tubes for fuel cladding applications. At Oak Ridge National Laboratory, experimental capabilities are under development to characterize the modulus, microcracking, and hermeticity of as-fabricated, as-irradiated SiC/SiC composite tubes. Resonant ultrasound spectroscopy has been validated as a promising technique to evaluate the elastic properties of SiC/SiC composite tubes and microcracking within the material. A similar technique, impulse excitation, is efficient in determining the basic mechanical properties of SiC bars prepared by chemical vapor deposition; it also has potential for application in studying the mechanical properties of SiC/SiC composite tubes. Complete evaluation of the quality of the developed coatings, a major mitigation strategy against gas permeation and hydrothermal corrosion, requires the deployment of various experimental techniques, such as scratch indentation, tensile pulling-off tests, and scanning electron microscopy. In addition, a comprehensive permeation test station is being established to assess the hermeticity of SiC/SiC composite tubes and to determine the H/D/He permeability of SiC/SiC composites. This report summarizes the current status of the development of these experimental capabilities.

The Future of Nearshore Processes Research

Science.gov (United States)

Elko, N.; Feddersen, F.; Foster, D. L.; Holman, R. A.; McNinch, J.; Ozkan-Haller, H. T.; Plant, N. G.; Raubenheimer, B.; Elgar, S.; Hay, A. E.; Holland, K. T.; Kirby, J. T., Jr.; Lippmann, T. C.; Miller, J. K.; Stockdon, H. F.; Ashton, A. D.; Boehm, A. B.; Clark, D.; Cowen, E.; Dalyander, S.; Gelfenbaum, G. R.; Hapke, C. J.; MacMahan, J.; McNamara, D.; Mulligan, R. P.; Palmsten, M. L.; Ruggiero, P.; Sherwood, C. R.; Hsu, T. J.

2014-12-01

Over 70 members of the nearshore coastal processes research community convened in April 2014 to discuss a vision for the future of nearshore science while celebrating the memories and contributions of our recently departed colleague, Abby Sallenger. The participants reviewed community accomplishments over the past four decades. Federal agencies, including FEMA, NOAA, NPS, USGS, USACE, and NRL discussed the most pressing societal needs within the coastal zone. The group engaged in a retrospective of the last four decades of progress, assessed the current status and limitations of nearshore processes research, and developed a vision for the future that focuses on societally relevant problems. The top research topics identified included: Long-term Coastal Impacts: Meaningfully improve our understanding and prediction of the long-term coastal effects of sea level rise and changes in storminess patterns and associated efforts to protect coastal infrastructure. Extreme Events: Coastal flooding, overland flow, and concurrent morphological evolution during extreme events including the subsequent process of coastal recovery. Human and Ecosystem Health: Linkages between physical coastal processes (transport and mixing) and land-based pollution (pathogens, nutrients, toxic contaminants). Critical for addressing these research questions is enabling infrastructure, such as new observational tools and data sets, models, and nearshore-community communication and collaboration. Idea and concepts developed during the meeting (to be published in Shore and Beach) will be presented to foster collaboration and advocacy amongst the wider nearshore community. Meeting materials are available at: https://scripps.ucsd.edu/centers/nearshorefuture/.

Proceedings of the Meeting of the Coastal Engineering Research Board (46th) Held in Vicksburg, Mississippi on 21-22 October 1986.

Science.gov (United States)

1987-06-01

to conduct site visits and review the use of ACE and other coastal microcomputer applications within the Corps coastal community . Meetings for the...that endeavor may be useful towards expediting the establishment of a similar network for the Corps coastal community . Several attendees at this

Materials and devices for quantum information processing in Si/SiGe

Energy Technology Data Exchange (ETDEWEB)

Sailer, Juergen

2010-12-15

In this thesis, we cover and discuss the complete way from material science, the fabrication of two-dimensional electron systems (2DES) in Si/SiGe heterostructures in molecular beam epitaxy (MBE), to quantum effects in few-electron devices based on these samples. We applied and compared two different approaches for the creation of pseudo-substrates that are as smooth, relaxed and defect free as possible. In the 'graded buffer' concept, starting from pure Si, the Ge content of the SiGe alloy is slowly and linearly increased until the desired Ge content is reached. In contrast, in the so-called 'low-temperature Si' concept, the SiGe alloy is deposited directly with the final Ge content, but onto a layer of highly defective Si. In terms of crystal defects, the 'graded buffer' turned out to be superior in comparison to the 'low-temperature Si' concept at the expense of a significantly higher material consumption. By continued optimization of the growth process, aiming at reducing the influence of the impurity, it nevertheless became possible to improve the charge carrier mobility from a mere 2000 cm{sup 2}/(Vs) to a record mobility exceeding 100 000 cm{sup 2}/(Vs). Within this work, we extended our MBE system with an electron beam evaporator for nuclear spin free {sup 28}Si. Together with the already existing effusion cell for {sup 70}Ge we were able to realize first 2DES in a nuclear spin free environment after successfully putting it to operation. The highest mobility 2DES in a nuclear spin free environment which have been realized in this thesis exhibited electron mobilities of up to 55 000 cm{sup 2}/(Vs). Quantum effects in Si/SiGe have been investigated in two- and zero-dimensional nanostructures. A remarkable phenomenon in the regime of the integer quantum Hall effect in Si/SiGe 2DES has been discovered and researched. For applications in quantum information processing and for the creation of qubits it is mandatory to

Design, fabrication and transportation of Si rotating device

International Nuclear Information System (INIS)

Kimura, Nobuaki; Imaizumi, Tomomi; Takemoto, Noriyuki; Tanimoto, Masataka; Saito, Takashi; Hori, Naohiko; Tsuchiya, Kunihiko; Romanova, Nataliya; Gizatulin, Shamil; Martyushov, Alexandr; Nakipov, Darkhan; Chakrov, Petr; Tanaka, Futoshi; Nakajima, Takeshi

2012-06-01

Si semiconductor production by Neutron Transmutation Doping (NTD) method using the Japan Materials Testing Reactor (JMTR) has been investigated in Neutron Irradiation and Testing Reactor Center, Japan Atomic Energy Agency (JAEA) in order to expand industry use. As a part of investigations, irradiation test of silicon ingot for development of NTD-Si with high quality was planned using WWR-K in Institute of Nuclear Physics (INP), National Nuclear Center of Republic of Kazakhstan (NNC-RK) based on one of specific topics of cooperation (STC), Irradiation Technology for NTD-Si (STC No.II-4), on the implementing arrangement between NNC-RK and the JAEA for 'Nuclear Technology on Testing/Research Reactors' in cooperation in research and development in nuclear energy and technology. As for the irradiation test, Si rotating device was fabricated in JAEA, and the fabricated device was transported with irradiation specimens from JAEA to INP-NNC-RK. This report described the design, the fabrication, the performance test of the Si rotating device and transportation procedures. (author)

Geoid determination in the coastal areas of the Gulf of Mexico

Science.gov (United States)

Song, HongZhi

continuous map of gravity anomalies and a continuous map of gravity by using spatial interpolation methods and to evaluate errors; 2) to solve the Laplace boundary value problem and evaluate errors; 3) to evaluate precision of the local geoid by using geospatial statistical tools and numerical techniques. This dissertation investigates modeling of the geoid, especially the gravimetric equipotential surface that approximates mean sea level, in the coastal areas of the Gulf of Mexico as well as errors in the geoid determination. The document begins with Chapter 1 which introduces the study of this dissertation. Different models of kriging are used to determine the precision of the geoid based on the free-air gravity anomalies data supplied by United States Naval Research Laboratory and the airborne gravity data provided by the U.S. National Geodetic Survey, which can be found in Chapters 2 and 3. Research in Chapters 2 shows that more precise evaluation of errors in gravity anomalies can be achieved by using different models of kriging. Results from Chapters 2 and 3 show that ordinary kriging with the stable semivariogram model provide better predictions. Research results from Chapter 3 provide estimation of maximum possible errors in the calculation of the geoid undulation. The dissertation also investigates behavior of gravity equipotential surfaces around coastal lines and its impact on the geoid evaluation. Chapters 4 and 5 are about evaluation of errors in the Dirichlet problem for calculation of gravity potential with uncertain boundary and boundary values has been achieved by solving the Laplace equation by means of separation of variables. Research has provided a theoretical model in Chapter 4 to estimate very small changes in gravimetric potential relative to the coast. Maximum possible error in the solution of Direchlet problem is determined in Chapter 5. Maximum possible error depends on the errors of boundary values and the precision of the boundary itself. Chapter

Microstructure and Mechanical Property of SiCf/SiC and Cf/SiC Composites

International Nuclear Information System (INIS)

Lee, S P; Cho, K S; Lee, H U; Lee, J K; Bae, D S; Byun, J H

2011-01-01

The mechanical properties of SiC based composites reinforced with different types of fabrics have been investigated, in conjunction with the detailed analyses of their microstructures. The thermal shock properties of SiC f /SiC composites were also examined. All composites showed a dense morphology in the matrix region. Carbon coated PW-SiC f /SiC composites had a good fracture energy, even if their strength was lower than that of PW-C f /SiC composites. SiC f /SiC composites represented a great reduction of flexural strength at the thermal shock temperature difference of 300 deg. C.

Comprehensive assessment of coastal eutrophication in Taiwan and its implications for management strategy.

Science.gov (United States)

Liu, Ta-Kang; Chen, Ping; Chen, Hou-Yu

2015-08-15

Due to the rapid population growth, anthropogenic activities result in agricultural, industrial, and urban diffuse runoffs that elevate the level of nutrients such as nitrogen and phosphorus in coastal waters. Currently there is no integrated analysis for coastal eutrophication in Taiwan. A comprehensive analysis of the coastal eutrophic status was performed in this study based on decade-long coastal water quality monitoring data from Taiwan's Environmental Protection Administration. A 3-tiered monitoring strategy is recommended based on the severity of the current eutrophication state. Results indicate that the most problematic area of coastal eutrophication is located in the estuary of the Donggang River (DGR) and its adjacent coastal waters, i.e., the Kao-Ping mouth (KPM) and Dapeng Bay (DPB) in south-western Taiwan. With a worsening eutrophic status, these areas demand intensive monitoring and research with higher spatial and temporal resolutions to evaluate the stresses of nutrient forcing and predict possible future responses. Copyright © 2015 Elsevier Ltd. All rights reserved.

Rare-earth element doped Si3N4/SiC micro/nano-composites-RT and HT mechanical properties

Czech Academy of Sciences Publication Activity Database

Lojanová, Š.; Tatarko, P.; Chlup, Zdeněk; Hnatko, M.; Dusza, J.; Lenčéš, Z.; Šajgalík, P.

2010-01-01

Roč. 30, č. 9 (2010), s. 1931-1944 ISSN 0955-2219 Institutional research plan: CEZ:AV0Z20410507 Keywords : Si3N4 * SiC * Nano-composites * Fracture toughness * Hardness * Strength * Creep Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass Impact factor: 2.574, year: 2010

Unbounded boundaries and shifting baselines: Estuaries and coastal seas in a rapidly changing world

Science.gov (United States)

Little, S.; Spencer, K. L.; Schuttelaars, H. M.; Millward, G. E.; Elliott, M.

2017-11-01

This Special Issue of Estuarine, Coastal and Shelf Science presents contributions from ECSA 55; an international symposium organised by the Estuarine and Coastal Sciences Association (ECSA) and Elsevier on the broad theme of estuaries and coastal seas in times of intense change. The objectives of the SI are to synthesise, hypothesise and illustrate the impacts of global change on estuaries and coastal seas through learning lessons from the past, discussing the current and forecasting for the future. It is highlighted here that establishing impacts and assigning cause to the many pressures of global change is and will continue to be a formidable challenge in estuaries and coastal seas, due in part to: (1) their complexity and unbounded nature; (2) difficulties distinguishing between human-induced changes and natural variations and; (3) multiple pressures and effects. The contributing authors have explored a number of these issues over a range of disciplines. The complexity and connectivity of estuaries and coastal seas have been investigated through studies of physicochemical and ecological components, whilst the human imprint on the environment has been identified through a series of predictive, contemporary, historical and palaeo approaches. The impact of human activities has been shown to occur over a range of spatial and temporal scales, requiring the development of integrated management approaches. These 30 articles provide an important contribution to our understanding and assessment of the impacts of global change. The authors highlight methods for essential management/mitigation of the consequences of global change and provide a set of directions, ideas and observations for future work. These include the need to consider: (1) the cumulative, synergistic and antagonistic effects of multiple pressures; (2) the importance of unbounded boundaries and connectivity across the aquatic continuum; (3) the value of combining cross-disciplinary palaeo, contemporary and

Risk Analysis of Coastal Disaster of Semarang City, Indonesia

Science.gov (United States)

Sunaryo; Ambariyanto; Sugianto, Denny Nugroho; Helmi, Muhammad; Kaimuddin, Awaluddin Halirin; Indarjo, Agus

2018-02-01

Coastal areas are highly vulnerable to disasters, as they are affected by events occurring both on land and at sea. In the development of cities in these areas, information on vulnerability levels is needed as a consideration in determining policy. This study aims to identify potential vulnerability of Semarang city, and to investigate the potential of hazard and disaster risk levels of the city. The study was conducted in 17 villages in the northern coastal area of Semarang. The assessment approach used was score analysis to some variables, i.e geomorphology, erosion, coastal slope, waves and socio-economic aspects. The research showed that the highest level of coastal vulnerability in the Semarang city were at three villages i.e.Terboyo Kulon, Terboyo Wetan and Trimulyo with value of 4.5; while the lowest level were at the Maron beach, Marina beach and Tanah Mas with value of 2.8. The highest potential coastal hazard in the Semarang city were at two villages i.e. Tanjung Mas and Tambak Lorok with value of 4.5; and the lowest value were in the village of Randugarut, Karanganyar, Tugurejo, Marina beach and Tanah Mas with value of 1.25.The highest level of coastal risk in the Semarang city were in the Trimulyo village with value of 3.13; and the lowest level were in the Marina beach and Tanah mas with value of 1.32.

Analysis of the High Conversion Efficiencies β-FeSi2 and BaSi2 n-i-p Thin Film Solar Cells

International Nuclear Information System (INIS)

Huang, J.Sh.; Lee, K.W.; Tseng, Y.H.

2014-01-01

Both β-FeSi 2 and BaSi 2 are silicides and have large absorption coefficients; thus they are very promising Si-based new materials for solar cell applications. In this paper, the dc I-V characteristics of n-Si/i-βFeSi 2 /p-Si and n-Si/i-BaSi 2 /p-Si thin film solar cells are investigated by solving the charge transport equations with optical generations. The diffusion current densities of free electron and hole are calculated first. Then the drift current density in the depletion regions is obtained. The total current density is the sum of diffusion and drift current densities. The conversion efficiencies are obtained from the calculated I-V curves. The optimum conversion efficiency of n-Si/i-βFeSi 2 /p-Si thin film solar cell is 27.8% and that of n-Si/i-BaSi 2 /p-Si thin film solar cell is 30.4%, both are larger than that of Si n-i-p solar cell (η is 20.6%). These results are consistent with their absorption spectrum. The calculated conversion efficiency of Si n-i-p solar cell is consistent with the reported researches. Therefore, these calculation results are valid in this work.

Analysis of the High Conversion Efficiencies β-FeSi2 and BaSi2 n-i-p Thin Film Solar Cells

Directory of Open Access Journals (Sweden)

Jung-Sheng Huang

2014-01-01

Full Text Available Both β-FeSi2 and BaSi2 are silicides and have large absorption coefficients; thus they are very promising Si-based new materials for solar cell applications. In this paper, the dc I-V characteristics of n-Si/i-βFeSi2/p-Si and n-Si/i-BaSi2/p-Si thin film solar cells are investigated by solving the charge transport equations with optical generations. The diffusion current densities of free electron and hole are calculated first. Then the drift current density in the depletion regions is obtained. The total current density is the sum of diffusion and drift current densities. The conversion efficiencies are obtained from the calculated I-V curves. The optimum conversion efficiency of n-Si/i-βFeSi2/p-Si thin film solar cell is 27.8% and that of n-Si/i-BaSi2/p-Si thin film solar cell is 30.4%, both are larger than that of Si n-i-p solar cell (η is 20.6%. These results are consistent with their absorption spectrum. The calculated conversion efficiency of Si n-i-p solar cell is consistent with the reported researches. Therefore, these calculation results are valid in this work.

Effect of Si on the reversibility of stress-induced martensite in Fe-Mn-Si shape memory alloys

Energy Technology Data Exchange (ETDEWEB)

Stanford, N. [Centre for Material and Fibre Innovation, Deakin University, Geelong, Victoria 3217 (Australia); Dunne, D.P., E-mail: druce_dunne@uow.edu.au [Faculty of Engineering, University of Wollongong, Wollongong, NSW 2522 (Australia)

2010-12-15

Fe-Mn-Si is a well-characterized ternary shape memory alloy. Research on this alloy has consistently shown that the addition of 5-6 wt.% Si is desirable to enhance the reversibility of stress-induced martensite vis-a-vis shape memory. This paper examines the effect of Si on the morphology and the crystallography of the martensite in the Fe-Mn-Si system. It is concluded that the addition of Si increases the c/a ratio of the martensite, reduces the transformation volume change and decreases the atomic spacing difference between the parallel close-packed directions in the austenite-martensite interface (habit) plane. It is proposed that, in addition to austenite strengthening, Si enhances reversibility by reducing the volume change and the interfacial atomic mismatch between the martensite and the austenite. Although shape memory is improved, transformation reversibility remains limited by the necessary misfit dislocations that accommodate the atomic spacing differences in the interface.

Effect of Si on the reversibility of stress-induced martensite in Fe-Mn-Si shape memory alloys

International Nuclear Information System (INIS)

Stanford, N.; Dunne, D.P.

2010-01-01

Fe-Mn-Si is a well-characterized ternary shape memory alloy. Research on this alloy has consistently shown that the addition of 5-6 wt.% Si is desirable to enhance the reversibility of stress-induced martensite vis-a-vis shape memory. This paper examines the effect of Si on the morphology and the crystallography of the martensite in the Fe-Mn-Si system. It is concluded that the addition of Si increases the c/a ratio of the martensite, reduces the transformation volume change and decreases the atomic spacing difference between the parallel close-packed directions in the austenite-martensite interface (habit) plane. It is proposed that, in addition to austenite strengthening, Si enhances reversibility by reducing the volume change and the interfacial atomic mismatch between the martensite and the austenite. Although shape memory is improved, transformation reversibility remains limited by the necessary misfit dislocations that accommodate the atomic spacing differences in the interface.

Magnetron-sputter epitaxy of β-FeSi2(220)/Si(111) and β-FeSi2(431)/Si(001) thin films at elevated temperatures

International Nuclear Information System (INIS)

Liu Hongfei; Tan Chengcheh; Chi Dongzhi

2012-01-01

β-FeSi 2 thin films have been grown on Si(111) and Si(001) substrates by magnetron-sputter epitaxy at 700 °C. On Si(111), the growth is consistent with the commonly observed orientation of [001]β-FeSi 2 (220)//[1-10]Si(111) having three variants, in-plane rotated 120° with respect to one another. However, on Si(001), under the same growth conditions, the growth is dominated by [-111]β-FeSi 2 (431)//[110]Si(001) with four variants, which is hitherto unknown for growing β-FeSi 2 . Photoelectron spectra reveal negligible differences in the valance-band and Fe2p core-level between β-FeSi 2 grown on Si(111) and Si(001) but an apparent increased Si-oxidization on the surface of β-FeSi 2 /Si(001). This phenomenon is discussed and attributed to the Si-surface termination effect, which also suggests that the Si/Fe ratio on the surface of β-FeSi 2 (431)/Si(001) is larger than that on the surface of β-FeSi 2 (220)/Si(111).

Coastal Analysis, Mathews County, VA

Data.gov (United States)

Federal Emergency Management Agency, Department of Homeland Security — Coastal study as defined in FEMA Guides and Specifications, Appendix D: Guidance for coastal Flooding Analyses and Mapping submitted as a result of a coastal study....

USACE National Coastal Mapping Program Update

Science.gov (United States)

Sylvester, C.

2017-12-01

The Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX) formed in 1998 to support the coastal mapping and charting requirements of the USACE, NAVO, NOAA and USGS. This partnership fielded three generations of airborne lidar bathymeters, executed operational data collection programs within the U.S. and overseas, and advanced research and development in airborne lidar bathymetry and complementary technologies. JALBTCX executes a USACE Headquarters-funded National Coastal Mapping Program (NCMP). Initiated in 2004, the NCMP provides high-resolution, high-accuracy elevation and imagery data along the sandy shorelines of the U.S. on a recurring basis. NCMP mapping activities are coordinated with Federal mapping partners through the Interagency Working Group on Ocean and Coastal Mapping and the 3D Elevation Program. The NCMP, currently in it's third cycle, is performing operations along the East Coast in 2017, after having completed surveys along the Gulf Coast in 2016 and conducting emergency response operations in support of Hurricane Matthew. This presentation will provide an overview of JALBTCX, its history in furthering airborne lidar bathymetry technology to meet emerging mapping requirements, current NCMP operations and data products, and Federal mapping coordination activities.

Coastal zones : shifting shores, sharing adaptation strategies for coastal environments

Energy Technology Data Exchange (ETDEWEB)

Hay, J.E. [Waikato Univ. (New Zealand); Morneau, F.; Savard, J.P. [Ouranos, Montreal, PQ (Canada); Madruga, R.P. [Centre of Investigation on the Global Economy (Cuba); Leslie, K.R. [Caribbean Community Climate Change Centre (Belize); Agricole, W. [Ministry of Environment and Natural Resources (Seychelles); Burkett, V. [United States Geological Survey (United States)

2006-07-01

A parallel event to the eleventh Conference of Parties (COP) to the United Nations Framework Convention of Climate Change was held to demonstrate examples of adaptation from around the world in the areas of food security, water resources, coastal zones, and communities/infrastructure. Panels on each theme presented examples from developing countries, countries in economic transition, and developed countries. These 4 themes were chosen because both mitigation and adaptation are essential to meeting the challenge of climate change. The objective of the event was to improve the knowledge of Canada's vulnerabilities to climate change, identify ways to minimize the negative effects of future impacts, and explore opportunities that take advantage of any positive impacts. This third session focused on how coastal communities are adapting to climate change in such places as Quebec, the Caribbean, and small Island States. It also presented the example of how a developed country became vulnerable to Hurricane Katrina which hit the coastal zone in the United States Gulf of Mexico. The presentations addressed the challenges facing coastal communities along with progress in risk assessment and adaptation both globally and in the Pacific. Examples of coastal erosion in Quebec resulting from climate change were presented along with climate change and variability impacts over the coastal zones of Seychelles. Cuba's vulnerability and adaptation to climate change was discussed together with an integrated operational approach to climate change, adaptation, biodiversity and land utilization in the Caribbean region. The lessons learned from around the world emphasize that adaptation is needed to reduce unavoidable risks posed by climate change and to better prepare for the changes ahead. refs., tabs., figs.

Visualizing Coastal Erosion, Overwash and Coastal Flooding in New England

Science.gov (United States)

Young Morse, R.; Shyka, T.

2017-12-01

Powerful East Coast storms and their associated storm tides and large, battering waves can lead to severe coastal change through erosion and re-deposition of beach sediment. The United States Geological Survey (USGS) has modeled such potential for geological response using a storm-impact scale that compares predicted elevations of hurricane-induced water levels and associated wave action to known elevations of coastal topography. The resulting storm surge and wave run-up hindcasts calculate dynamic surf zone collisions with dune structures using discrete regime categories of; "collision" (dune erosion), "overwash" and "inundation". The National Weather Service (NWS) recently began prototyping this empirical technique under the auspices of the North Atlantic Regional Team (NART). Real-time erosion and inundation forecasts were expanded to include both tropical and extra-tropical cyclones along vulnerable beaches (hotspots) on the New England coast. Preliminary results showed successful predictions of impact during hurricane Sandy and several intense Nor'easters. The forecasts were verified using observational datasets, including "ground truth" reports from Emergency Managers and storm-based, dune profile measurements organized through a Maine Sea Grant partnership. In an effort to produce real-time visualizations of this forecast output, the Northeastern Regional Association of Coastal Ocean Observing Systems (NERACOOS) and the Gulf of Maine Research Institute (GMRI) partnered with NART to create graphical products of wave run-up levels for each New England "hotspot". The resulting prototype system updates the forecasts twice daily and allows users the ability to adjust atmospheric and sea state input into the calculations to account for model errors and forecast uncertainty. This talk will provide an overview of the empirical wave run-up calculations, the system used to produce forecast output and a demonstration of the new web based tool.

Going coastal: shared evolutionary history between coastal British Columbia and Southeast Alaska wolves (Canis lupus.

Directory of Open Access Journals (Sweden)

Byron V Weckworth

2011-05-01

Full Text Available Many coastal species occupying the temperate rainforests of the Pacific Northwest in North America comprise endemic populations genetically and ecologically distinct from interior continental conspecifics. Morphological variation previously identified among wolf populations resulted in recognition of multiple subspecies of wolves in the Pacific Northwest. Recently, separate genetic studies have identified diverged populations of wolves in coastal British Columbia and coastal Southeast Alaska, providing support for hypotheses of distinct coastal subspecies. These two regions are geographically and ecologically contiguous, however, there is no comprehensive analysis across all wolf populations in this coastal rainforest.By combining mitochondrial DNA datasets from throughout the Pacific Northwest, we examined the genetic relationship between coastal British Columbia and Southeast Alaska wolf populations and compared them with adjacent continental populations. Phylogenetic analysis indicates complete overlap in the genetic diversity of coastal British Columbia and Southeast Alaska wolves, but these populations are distinct from interior continental wolves. Analyses of molecular variation support the separation of all coastal wolves in a group divergent from continental populations, as predicted based on hypothesized subspecies designations. Two novel haplotypes also were uncovered in a newly assayed continental population of interior Alaska wolves.We found evidence that coastal wolves endemic to these temperate rainforests are diverged from neighbouring, interior continental wolves; a finding that necessitates new international strategies associated with the management of this species.

Recent progress in Si thin film technology for solar cells

Science.gov (United States)

Kuwano, Yukinori; Nakano, Shoichi; Tsuda, Shinya

1991-11-01

Progress in Si thin film technology 'specifically amorphous Si (a-Si) and polycrystalline Si (poly-Si) thin film' for solar cells is summarized here from fabrication method, material, and structural viewpoints. In addition to a-Si, primary results on poly-Si thin film research are discussed. Various applications for a-Si solar cells are mentioned, and consumer applications and a-Si solar cell photovoltaic systems are introduced. New product developments include see-through solar cells, solar cell roofing tiles, and ultra-light flexible solar cells. As for new systems, air conditioning equipment powered by solar cells is described. Looking to the future, the proposed GENESIS project is discussed.

Beyond the Floodplain: Drivers of Flood Risk in Coastal Cities

Science.gov (United States)

Rosenzweig, B.; McPhearson, T.; Rosi, E. J.

2017-12-01

While the catastrophic impacts of Hurricane Katrina increased awareness of coastal flood risk, conventional approaches to flood risk assessment do not adequately represent the drivers of flood risk in the unique, highly engineered landscape of dense cities. We review the recent (1996-2016) history of flooding events and current regional climate change projection for 4 diverse coastal cities in the United States: San Juan, Miami, Baltimore and New York. Our review suggests that while all 4 of these cities face increased risk from direct coastal flooding with climate change, pluvial flooding will be an additional, important driver of risk that is currently poorly quantified. Unlike other types of flooding, pluvial flood risk is not limited to a contiguous riverine or coastal floodplain, but is instead driven by interactions between spatially variable geophysical drivers (intense rainfall, shallow groundwater, and influent tidal water), social drivers (patterns of land use) and technical drivers (urban stormwater and coastal infrastructure). We discuss approaches for quantitative assessment of pluvial flood risk, the challenges presented by the lack of data on geophysical flooding drivers in dense cities, and opportunities for integrated research to provide the scientific information needed by practitioners.

77 FR 40586 - Coastal Programs Division

Science.gov (United States)

2012-07-10

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration Coastal Programs Division AGENCY: Coastal Programs Division, Office of Ocean and Coastal Resource Management, National Ocean.... FOR FURTHER INFORMATION CONTACT: Kerry Kehoe, Coastal Programs Division (NORM/3), Office of Ocean and...

Investigation of γ-radiation defect formation at the Si-SiO2 interface

International Nuclear Information System (INIS)

Zaynabidinov, S.; Yulchiev, Sh.; Aliev, R.

2004-01-01

Full text: In work the results of an experimental research of process radiating defects formation on border are submitted undressed Si-SiO 2 at γ-radiation of the silicon MOS structures. As against similar researches the basic attention is given on the analysis of generation-recombination characteristics of structures, that allowed to establish character of the defects formation both on border undressed Si-SiO 2 , and in about border of Si. In experiments the structures received by thermal oxidation at T=1000 deg. C in environment of dry oxygen n-Si substrates with specific resistance ρ=0.3 Ω·cm are used. The thickness of oxygen layer made ∼0.1 μm. The test MOS-structures with an aluminium electrode and area ∼0.01 cm 2 irradiated with γ-quanta from the 60 Co source by a dose of 10 6 rad. The choice of a dose of an radiation is caused by that at such dose the essential increase of concentration of superficial defects is observed, and at the same time there are no significant changes of parameters of a substrate because of formation of point defects in volume of silicon. The generation characteristics of structures such, as speed of superficial generation s and time of life τ g of carriers of a charge in about surface before and after an radiation defined by a method isothermal relaxation of nonequilibrium high-frequency capacity. The relaxation of nonequilibrium capacity registered at submission on translating structure in a condition of deeper inversion. Such mode of measurement allows to neglect the contribution which is brought in recharged of superficial condition in superficial generation currents. Are received relaxation dependence of structures before and after an radiation, and also spectra of distribution of density of superficial condition on width of the forbidden zone Si dN ss /dE. The increase at 12-15 of time of concentration of superficial condition with E=E c -(0.18±0.03) eV in the irradiated structures is established. Such condition is

Advanced Environmental Barrier Coating Development for SiC/SiC Ceramic Matrix Composites: NASA's Perspectives

Science.gov (United States)

Zhu, Dongming

2016-01-01

This presentation reviews NASA environmental barrier coating (EBC) system development programs and the coating materials evolutions for protecting the SiC/SiC Ceramic Matrix Composites in order to meet the next generation engine performance requirements. The presentation focuses on several generations of NASA EBC systems, EBC-CMC component system technologies for SiC/SiC ceramic matrix composite combustors and turbine airfoils, highlighting the temperature capability and durability improvements in simulated engine high heat flux, high pressure, high velocity, and with mechanical creep and fatigue loading conditions. The current EBC development emphasis is placed on advanced NASA 2700F candidate environmental barrier coating systems for SiC/SiC CMCs, their performance benefits and design limitations in long-term operation and combustion environments. Major technical barriers in developing environmental barrier coating systems, the coating integrations with next generation CMCs having the improved environmental stability, erosion-impact resistance, and long-term fatigue-environment system durability performance are described. The research and development opportunities for advanced turbine airfoil environmental barrier coating systems by utilizing improved compositions, state-of-the-art processing methods, and simulated environment testing and durability modeling are discussed.

Use of thermodynamic calculation to predict the effect of Si on the ageing behavior of Al-Mg-Si-Cu alloys

International Nuclear Information System (INIS)

Ji, Yanli; Zhong, Hao; Hu, Ping; Guo, Fuan

2011-01-01

Research highlights: → Thermodynamic calculation can predict the ageing behavior of 6xxx alloys. → The hardness level of the alloys depends on the Si content in as-quenched matrix. → The precipitation strengthening effect depends on the Mg 2 Si level of the alloys. -- Abstract: Thermodynamic calculation was employed to predict the influence of Si content on the ageing behavior of Al-Mg-Si-Cu alloys. In addition, experiments were carried out to verify the predictions. The results show that thermodynamic calculation can predict the effect of Si content on the ageing behavior of the studied alloys. This study further proposes that the hardness level of alloys during ageing is directly related to the Si content in the as-quenched supersaturated solution, while the precipitation strengthening effect is directly related to the Mg 2 Si level of the alloys.

Integrated Coastal Data at NOAA's National Centers for Environmental Information (NCEI)

Science.gov (United States)

Stroker, K. J.; Mesick, S.

2016-02-01

The National Centers for Environmental Information (NCEI) provides stewardship for the world's largest collection of data enabling communities to ensure preparedness and resilience to coastal hazards. In this unique collection, NCEI has the responsibility to ensure access to high-resolution coastal tide gauge data, coastal bathymetry and topography data, global geologic hazards data (tsunami, earthquakes, and volcanic eruptions) as part of the World Data Center for Geophysics, and are expanding the archive to support other coastal data streams, such as coastal current velocity data important for safety in ports and harbors. These data, collected by partners from academia, federal and state governments, support a wide variety of uses. Ensuring accurate, high quality metadata for these data are essential for their proper use. In addition to providing easy access to partner data to extend the use of these data, NCEI also develops scientifically-validated derived products. One such example is our collection of high-resolution, coastal digital elevation models (DEMs) that integrate ocean bathymetry and land topography to support NOAA's mission to understand and predict changes in Earth's environment, and conserve and manage coastal and marine resources to meet our Nation's economic, social, and environmental needs. These DEMs can be used for modeling of coastal processes (tsunami inundation, storm surge, sea-level rise, contaminant dispersal, etc.), ecosystems management and habitat research, coastal and marine spatial planning, and hazard mitigation and community preparedness. Additionally, the US Extended Continental Shelf (ECS) project is determining the outer limits of the US continental shelf though the collection and analysis of data that describe the depth, shape and geophysical characteristics of the seabed and sub-seafloor. These data are all housed and stewarded at NCEI. The paper will discuss the wide variety of coastal data maintained and stewarded at NCEI

SiC Nanoparticles Toughened-SiC/MoSi2-SiC Multilayer Functionally Graded Oxidation Protective Coating for Carbon Materials at High Temperatures

Science.gov (United States)

Abdollahi, Alireza; Ehsani, Naser; Valefi, Zia; Khalifesoltani, Ali

2017-05-01

A SiC nanoparticle toughened-SiC/MoSi2-SiC functionally graded oxidation protective coating on graphite was prepared by reactive melt infiltration (RMI) at 1773 and 1873 K under argon atmosphere. The phase composition and anti-oxidation behavior of the coatings were investigated. The results show that the coating was composed of MoSi2, α-SiC and β-SiC. By the variations of Gibbs free energy (calculated by HSC Chemistry 6.0 software), it could be suggested that the SiC coating formed at low temperatures by solution-reprecipitation mechanism and at high temperatures by gas-phase reactions and solution-reprecipitation mechanisms simultaneously. SiC nanoparticles could improve the oxidation resistance of SiC/MoSi2-SiC multiphase coating. Addition of SiC nanoparticles increases toughness of the coating and prevents spreading of the oxygen diffusion channels in the coating during the oxidation test. The mass loss and oxidation rate of the SiC nanoparticle toughened-SiC/MoSi2-SiC-coated sample after 10-h oxidation at 1773 K were only 1.76% and 0.32 × 10-2 g/cm3/h, respectively.

Reliability implications of defects in high temperature annealed Si/SiO2/Si structures

International Nuclear Information System (INIS)

Warren, W.L.; Fleetwood, D.M.; Shaneyfelt, M.R.; Winokur, P.S.; Devine, R.A.B.; Mathiot, D.; Wilson, I.H.; Xu, J.B.

1994-01-01

High-temperature post-oxidation annealing of poly-Si/SiO 2 /Si structures such as metal-oxide-semiconductor capacitors and metal-oxide-semiconductor field effect transistors is known to result in enhanced radiation sensitivity, increased 1/f noise, and low field breakdown. The authors have studied the origins of these effects from a spectroscopic standpoint using electron paramagnetic resonance (EPR) and atomic force microscopy. One result of high temperature annealing is the generation of three types of paramagnetic defect centers, two of which are associated with the oxide close to the Si/SiO 2 interface (oxygen-vacancy centers) and the third with the bulk Si substrate (oxygen-related donors). In all three cases, the origin of the defects may be attributed to out-diffusion of O from the SiO 2 network into the Si substrate with associated reduction of the oxide. The authors present a straightforward model for the interfacial region which assumes the driving force for O out-diffusion is the chemical potential difference of the O in the two phases (SiO 2 and the Si substrate). Experimental evidence is provided to show that enhanced hole trapping and interface-trap and border-trap generation in irradiated high-temperature annealed Si/SiO 2 /Si systems are all related either directly, or indirectly, to the presence of oxygen vacancies

Strategy for integration of coastal culture in learning process of mathematics in junior high school

Science.gov (United States)

Suyitno, H.; Zaenuri; Florentinus, T. S.; Zakaria, E.

2018-03-01

Traditional life in the fishing family is part of the local culture. Many School-age children in the fishing family drop-outs due to lack of parents motivation and the environment was less supportive. The problems were: (1) How the strategy of integration of local culture in learning process of mathematics in Junior High School (JHS)? (2) How to prepare the Mathematics Student’s Book for grade 7 of JHS that based on coastal culture, that has an ISBN, has international level, applicable, and in accordance with the current curriculum? The purposes of this research were: (1) to obtain the strategy of integration of local culture in learning process of mathematics in JHS, through FGD between UNNES and UKM; (2) to obtain the experts validation, through Focus Group Discussion (FGD) between UNNES and UKM toward the draft of the Mathematics Student’s Book for grade 7 of JHS that based on coastal culture; (3) produces Mathematics Student’s Book for grade 7 SMP which based on coastal culture and has an ISBN, international, applicable, and in accordance with the curriculum. The research activity was a qualitative research, so that the research methods include: (1) data reduction, (2) display data, (3) data interpretation, and (4) conclusion/verification. The main activities of this research: drafting the Mathematics Student’s Book of Grade 7 which based on coastal culture; get the validation from international partners;conducting FGD at Education Faculty of Universiti Kebangsaan Malaysia through the program of visiting lecturers for getting the Mathematics Student’s Book of grade 7 which based on coastal culture, registering for ISBN, and publishing the reasearch results in International seminar and International Journals. The results of this research were as follows. (1) Getting a good strategy for integration of local culture in learning process of mathematics in JHS. (2) Getting the Mathematics Student’s Book for grade 7 of JHS that based on coastal culture

Nitridation of si using mechano-fusion method

International Nuclear Information System (INIS)

Li, Z. L.; Calka, A.; Williams, J. S.

1996-01-01

Full text: It has been found that silicon nitride (Si 3 N 4 ) can be formed by ball milling of Si in ammonia. However only small fraction of Si can be transformed into 1 Si 3 N 4 . The major milling effect is the formation of poly/nanocrystalline silicon. At this stage of research it is difficult to answer the question why ball milling causes only limited formation of Si 3 N 4 . It is due to little understanding of 1 processes occurring during milling. Therefore, the purpose of this work was to study nitridation reaction during milling of Si in ammonia. In particular the 1 effect of milling conditions such as milling energies, atmosphere and a form of starting material was studied. The micro/macrostructural development during milling and subsequent annealing was studied using x-ray diffractometry, thermal analysis, elemental analysis measurement. It was found that the transformed fraction of Si 3 N 4 compound is strongly dependent on milling energies and milling atmosphere

Resource-Based Capability on Development Knowledge Management Capabilities of Coastal Community

Science.gov (United States)

Teniwut, Roberto M. K.; Hasyim, Cawalinya L.; Teniwut, Wellem A.

2017-10-01

Building sustainable knowledge management capabilities in the coastal area might face a whole new challenge since there are many intangible factors involved from openness on new knowledge, access and ability to use the latest technology to the various local wisdom that still in place. The aimed of this study was to identify and analyze the resource-based condition of coastal community in this area to have an empirical condition of tangible and intangible infrastructure on developing knowledge management capability coastal community in Southeast Maluku, Indonesia. We used qualitative and quantitative analysis by depth interview and questionnaire for collecting the data with multiple linear regression as our analysis method. The result provided the information on current state of resource-based capability of a coastal community in this Southeast Maluku to build a sustainability model of knowledge management capabilities especially on utilization marine and fisheries resources. The implication of this study can provide an empirical information for government, NGO and research institution to dictate on how they conducted their policy and program on developing coastal community region.

Emerging methods for the study of coastal ecosystem landscape structure and change

Science.gov (United States)

Brock, John C.; Danielson, Jeffrey J.; Purkis, Sam

2013-01-01

Coastal landscapes are heterogeneous, dynamic, and evolve over a range of time scales due to intertwined climatic, geologic, hydrologic, biologic, and meteorological processes, and are also heavily impacted by human development, commercial activities, and resource extraction. A diversity of complex coastal systems around the globe, spanning glaciated shorelines to tropical atolls, wetlands, and barrier islands are responding to multiple human and natural drivers. Interdisciplinary research based on remote-sensing observations linked to process studies and models is required to understand coastal ecosystem landscape structure and change. Moreover, new techniques for coastal mapping and monitoring are increasingly serving the needs of policy-makers and resource managers across local, regional, and national scales. Emerging remote-sensing methods associated with a diversity of instruments and platforms are a key enabling element of integrated coastal ecosystem studies. These investigations require both targeted and synoptic mapping, and involve the monitoring of formative processes such as hydrodynamics, sediment transport, erosion, accretion, flooding, habitat modification, land-cover change, and biogeochemical fluxes.

Fabrication and Mechanical Properties of SiCw(p/SiC-Si Composites by Liquid Si Infiltration using Pyrolysed Rice Husks and SiC Powders as Precursors

Directory of Open Access Journals (Sweden)

Dan Zhu

2014-03-01

Full Text Available Dense silicon carbide (SiC matrix composites with SiC whiskers and particles as reinforcement were prepared by infiltrating molten Si at 1550 °C into porous preforms composed of pyrolysed rice husks (RHs and extra added SiC powder in different ratios. The Vickers hardness of the composites showed an increase from 18.6 to 21.3 GPa when the amount of SiC added in the preforms was 20% (w/w, and then decreased to 17.3 GPa with the increase of SiC added in the preforms up to 80% (w/w. The values of flexural strength of the composites initially decreased when 20% (w/w SiC was added in the preform and then increased to 587 MPa when the SiC concentration reached 80% (w/w. The refinement of SiC particle sizes and the improvement of the microstructure in particle distribution of the composites due to the addition of external SiC played an effective role in improving the mechanical properties of the composites.

Oscillations in the fusion of the Si + Si systems; Oscilaciones en la fusion de sistemas de Si + Si

Energy Technology Data Exchange (ETDEWEB)

Aguilera R, E F; Kolata, J J; DeYoung, P A; Vega, J J [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

1986-02-15

Excitation functions for the yields of all the residual nuclei from the {sup 28} Si + {sup 28,30} and {sup 30} Si + {sup 30} Si reactions have been measured via the {gamma}-ray technique for center of mass energies in the region within one and two times the Coulomb barrier.Thirteen elements were identified for the first reaction and ten for the other two. While no structure is shown by the data for the {sup 28} + {sup 28} Si reaction, we have found evidence for intermediate width structure in the 2{alpha} and the {alpha}pn channels in {sup 28} Si + {sup 30} Si and for broad structure in the total fusion cross sections for {sup 30} Si + {sup 30} Si. Calculations using a barrier penetration model with one free parameter reproduce the experimental results quite well. Evaporation model calculations indicate that the individual structure of the nuclei involved in the respective decay chains might have an important influence upon the deexcitation process at the energies relevant to our experiments. (Author)

Disentangling physical and biological drivers of phytoplankton dynamics in a coastal system.

Science.gov (United States)

Cianelli, Daniela; D'Alelio, Domenico; Uttieri, Marco; Sarno, Diana; Zingone, Adriana; Zambianchi, Enrico; d'Alcalà, Maurizio Ribera

2017-11-20

This proof-of-concept study integrates the surface currents measured by high-frequency coastal radars with plankton time-series data collected at a fixed sampling point from the Mediterranean Sea (MareChiara Long Term Ecological Research site in the Gulf of Naples) to characterize the spatial origin of phytoplankton assemblages and to scrutinize the processes ruling their dynamics. The phytoplankton community generally originated from the coastal waters whereby species succession was mainly regulated by biological factors (life-cycle processes, species-specific physiological performances and inter-specific interactions). Physical factors, e.g. the alternation between coastal and offshore waters and the horizontal mixing, were also important drivers of phytoplankton dynamics promoting diversity maintenance by i) advecting species from offshore and ii) diluting the resident coastal community so as to dampen resource stripping by dominant species and thereby increase the numerical importance of rarer species. Our observations highlight the resilience of coastal communities, which may favour their persistence over time and the prevalence of successional events over small time and space scales. Although coastal systems may act differently from one another, our findings provide a conceptual framework to address physical-biological interactions occurring in coastal basins, which can be generalised to other areas.

Going coastal: Shared evolutionary history between coastal British Columbia and Southeast Alaska wolves (canis lupus)

Science.gov (United States)

Weckworth, B.V.; Dawson, N.G.; Talbot, S.L.; Flamme, M.J.; Cook, J.A.

2011-01-01

Background: Many coastal species occupying the temperate rainforests of the Pacific Northwest in North America comprise endemic populations genetically and ecologically distinct from interior continental conspecifics. Morphological variation previously identified among wolf populations resulted in recognition of multiple subspecies of wolves in the Pacific Northwest. Recently, separate genetic studies have identified diverged populations of wolves in coastal British Columbia and coastal Southeast Alaska, providing support for hypotheses of distinct coastal subspecies. These two regions are geographically and ecologically contiguous, however, there is no comprehensive analysis across all wolf populations in this coastal rainforest. Methodology/Principal Findings: By combining mitochondrial DNA datasets from throughout the Pacific Northwest, we examined the genetic relationship between coastal British Columbia and Southeast Alaska wolf populations and compared them with adjacent continental populations. Phylogenetic analysis indicates complete overlap in the genetic diversity of coastal British Columbia and Southeast Alaska wolves, but these populations are distinct from interior continental wolves. Analyses of molecular variation support the separation of all coastal wolves in a group divergent from continental populations, as predicted based on hypothesized subspecies designations. Two novel haplotypes also were uncovered in a newly assayed continental population of interior Alaska wolves. Conclusions/Significance: We found evidence that coastal wolves endemic to these temperate rainforests are diverged from neighbouring, interior continental wolves; a finding that necessitates new international strategies associated with the management of this species. ?? 2011 This is an open-access article.

Using science to strengthen our Nation's resilience to tomorrow's challenges: understanding and preparing for coastal impacts

Science.gov (United States)

Simmons, Dale L.; Andersen, Matthew E.; Dean, Teresa A.; Focazio, Michael J.; Fulton, John W.; Haines, John W.; Mason, Jr., Robert R.; Tihansky, Ann B.; Young, John A.

2014-01-01

Hurricane Sandy caused unprecedented damage across some of the most densely populated coastal areas of the northeastern United States. The costly, landscape-altering destruction left in the wake of this storm is a stark reminder of our Nation’s need to become more resilient as we inevitably face future coastal hazards. As our Nation recovers from this devastating natural disaster, it is clear that accurate scientific information is essential as we seek to identify and develop strategies to address trends in coastal landscape change and reduce our future vulnerability to major storm events. To address this need, the U.S. Geological Survey (USGS) received $43.2 million in supplemental appropriations from the Department of the Interior (DOI) to conduct the scientific research needed to guide response, recovery, and rebuilding activities and to develop effective strategies for protecting coastal communities and resources in the future. This fact sheet describes how the USGS is combining interdisciplinary science with state-of-the-art technologies to achieve a comprehensive understanding of coastal change caused by Hurricane Sandy. By assessing coastal change impacts through research and by developing tools that enhance our science capabilities, support coastal stakeholders, and facilitate effective decision making, we continue to build a greater understanding of the processes at work across our Nation’s complex coastal environment—from wetlands, estuaries, barrier islands, and nearshore marine areas to infrastructure and human communities. This improved understanding will increase our resilience as we prepare for future short-term, extreme events as well as long-term coastal change.

Ocean and Coastal Law

Science.gov (United States)

Ross, David A.

First of all, this is not the typical book that one expects to see reviewed in Eos, but, read on. It should be clear, by now, even to the most esoteric geophysicist, that lawyers and jurists are taking very close looks at many coastal zone and offshore marine activities. More importantly, there are a wide variety of laws (both at the state and the national levels) and international regulations that determine how we now use or will use our coastal region including how and where we will do marine scientific research. Recently, a Presidential Proclamation (March 1983) declared a 200-mile exclusive economic zone for the United States. The President, in the accompanying statements to the Proclamation, has called special attention to polymetallic sulfide deposits (Is someone in the White House reading Eos?) in what will now be U.S. waters (i.e., the Juan de Fuca region). Well, if you or your colleagues want to know more about U.S. and individual state rules for management and use of our marine areas, this might be the book for you.

Analyses of the As doping of SiO{sub 2}/Si/SiO{sub 2} nanostructures

Energy Technology Data Exchange (ETDEWEB)

Ruffino, Francesco; Miritello, Maria [CNR-IMM MATIS, via S. Sofia 64, 95123 Catania (Italy); Tomasello, Mario Vincenzo [Scuola Superiore di Catania, via San Nullo 5/i, 95123 Catania (Italy); De Bastiani, Riccardo; Grimaldi, Maria Grazia [Dipartimento di Fisica ed Astronomia, Universita di Catania, via S. Sofia 64, 95123 Catania (Italy); CNR-IMM MATIS, via S. Sofia 64, 95123 Catania (Italy); Nicotra, Giuseppe; Spinella, Corrado [Consiglio Nazionale delle Ricerche-Istituto per la Microelettronica e Microsistemi (CNR-IMM), VIII Strada 5, 95121 Catania (Italy)

2011-03-15

We illustrate the behaviour of As when it is confined, by the implantation technique, in a SiO{sub 2}(70nm)/Si(30nm)/SiO{sub 2}(70nm) multilayer and its spatial redistribution when annealing processes are performed. By Rutherford backscattering spectrometry and Z-contrast transmission electron microscopy we found an As accumulation at the Si/SiO{sub 2} interfaces and at the Si grain boundaries with no segregation of the As in the Si layer. Such an effect is in agreement with a model that assumes a traps distribution in the Si in the first 2-3 nm above the SiO{sub 2}/Si interfaces and along the Si grain boundaries. The traps concentration at the Si/SiO{sub 2} interfaces was estimated in 10{sup 14} traps/cm{sup 2}. The outlined results can open perspectives on the doping properties of As in Si nanocrystals, whose applications in nanoelectronics and optoelectronics are widely investigated (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Technology computer aided design for Si, SiGe and GaAs integrated circuits

CERN Document Server

Armstrong, GA

2007-01-01

The first book to deal with a broad spectrum of process and device design, and modelling issues related to semiconductor devices, bridging the gap between device modelling and process design using TCAD. Examples for types of Si-, SiGe-, GaAs- and InP-based heterostructure MOS and bipolar transistors are compared with experimental data from state-of-the-art devices. With various aspects of silicon heterostructures, this book presents a comprehensive perspective of emerging fields and covers topics ranging from materials to fabrication, devices, modelling and applications. Aimed at research-and-

Contribution of changes in opal productivity and nutrient distribution in the coastal upwelling systems to Late Pliocene/Early Pleistocene climate cooling

Directory of Open Access Journals (Sweden)

J. Etourneau

2012-09-01

Full Text Available The global Late Pliocene/Early Pleistocene cooling (~3.0–2.0 million years ago – Ma concurred with extremely high diatom and biogenic opal production in most of the major coastal upwelling regions. This phenomenon was particularly pronounced in the Benguela upwelling system (BUS, off Namibia, where it is known as the Matuyama Diatom Maximum (MDM. Our study focuses on a new diatom silicon isotope (δ³⁰Si record covering the MDM in the BUS. Unexpectedly, the variations in δ³⁰Si signal follow biogenic opal content, whereby the highest δ³⁰Si values correspond to the highest biogenic opal content. We interpret the higher δ³⁰Si values during the MDM as a result of a stronger degree of silicate utilisation in the surface waters caused by high productivity of mat-forming diatom species. This was most likely promoted by weak upwelling intensity dominating the BUS during the Late Pliocene/Early Pleistocene cooling combined with a large silicate supply derived from a strong Southern Ocean nutrient leakage responding to the expansion of Antarctic ice cover and the resulting stratification of the polar ocean 3.0–2.7 Ma ago. A similar scenario is hypothesized for other major coastal upwelling systems (e.g. off California during this time interval, suggesting that the efficiency of the biological carbon pump was probably sufficiently enhanced in these regions during the MDM to have significantly increased the transport of atmospheric CO₂ to the deep ocean. In addition, the coeval extension of the area of surface water stratification in both the Southern Ocean and the North Pacific, which decreased CO₂ release to the atmosphere, led to further enhanced atmospheric CO₂ drawn-down and thus contributed significantly to Late Pliocene/Early Pleistocene cooling.

Boundary Conditions, Data Assimilation, and Predictability in Coastal Ocean Models

National Research Council Canada - National Science Library

Samelson, Roger M; Allen, John S; Egbert, Gary D; Kindle, John C; Snyder, Chris

2007-01-01

...: The specific objectives of this research are to determine the impact on coastal ocean circulation models of open ocean boundary conditions from Global Ocean Data Assimilation Experiment (GODAE...

Electrical control of a long-lived spin qubit in a Si/SiGe quantum dot

Science.gov (United States)

Kawakami, Erika

2015-03-01

increased our understanding and raised the prospects of spin qubits in Si/SiGe quantum dots. This work has been done in collaboration with T.M. J. Jullien, P. Scarlino, V.V. Dobrovitski, D.R. Ward, D. E. Savage, M. G. Lagally, Mark Friesen, S. N. Coppersmith, M. A. Eriksson, and L. M. K. Vandersypen. This work was supported in part by the Army Research Office (ARO) (W911NF-12-0607), the Foundation for Fundamental Research on Matter (FOM) and the European Research Council (ERC). Development and maintenance of the growth facilities used for fabricating samples was supported by the Department of Energy (DOE) (DE-FG02-03ER46028). E.K. was supported by a fellowship from the Nakajima Foundation. This research utilized NSF-supported shared facilities at the University of Wisconsin-Madison.

Research on design and firing performance of Si-based detonator

Directory of Open Access Journals (Sweden)

Rui-zhen Xie

2014-03-01

Full Text Available For the chip integration of MEMS (micro-electromechanical system safety and arming device, a miniature detonator needs to be developed to reduce the weight and volume of explosive train. A Si-based micro-detonator is designed and fabricated, which meets the requirement of MEMS safety and arming device. The firing sensitivity of micro-detonator is tested according to GJB/z377A-94 sensitivity test methods: Langlie. The function time of micro-detonator is measured using wire probe and photoelectric transducer. The result shows the average firing voltage is 6.4 V when the discharge capacitance of firing electro-circuit is 33 μF. And the average function time is 5.48 μs. The firing energy actually utilized by Si-based micro-detonator is explored.

24 CFR 574.645 - Coastal barriers.

Science.gov (United States)

2010-04-01

... 24 Housing and Urban Development 3 2010-04-01 2010-04-01 false Coastal barriers. 574.645 Section....645 Coastal barriers. In accordance with the Coastal Barrier Resources Act, 16 U.S.C. 3501, no financial assistance under this part may be made available within the Coastal Barrier Resources System. ...

Quantification of intensive hybrid coastal reclamation for revealing its impacts on macrozoobenthos

International Nuclear Information System (INIS)

Yan, Jiaguo; Cui, Baoshan; Zheng, Jingjing; Xie, Tian; Wang, Qing; Li, Shanze

2015-01-01

Managing and identifying the sources of anthropogenic stress in coastal wetlands requires an in-depth understanding of relationships between species diversity and human activities. Empirical and experimental studies provide clear evidence that coastal reclamation can have profound impacts on marine organisms, but the focus of such studies is generally on comparative or laboratory research. We developed a compound intensity index (reclamation intensity index, RI) on hybrid coastal reclamation, to quantify the impacts of reclamation on coastal ecosystems. We also made use of mean annual absolute changes to a number of biotic variables (biodiversity, species richness, biomass of total macrozoobenthos, and species richness and biomass of Polychaeta, Mollusca, Crustacea, and Echinodermata) to determine Hedges’d index, which is a measure of the potential effects of coastal reclamation. Our results showed that there was significant difference of coastal reclamation intensity between Yellow Sea, East China Sea and South China Sea, the biological changes in effect sizes of the three regions differed greatly over time. Our modelling analyses showed that hybrid coastal reclamation generally had significant negative impacts on species diversity and biomass of macrozoobenthos. These relationships varied among different taxonomic groups and included both linear and nonlinear relationships. The results indicated that a high-intensity of coastal reclamation contributed to a pronounced decline in species diversity and biomass, while lower-intensity reclamation, or reclamation within certain thresholds, resulted in a small increase in species diversity and biomass. These results have important implications for biodiversity conservation and the ecological restoration of coastal wetlands in face of the intensive reclamation activities. (letter)

Collections management plan for the U.S. Geological Survey Woods Hole Coastal and Marine Science Center Data Library

Science.gov (United States)

List, Kelleen M.; Buczkowski, Brian J.; McCarthy, Linda P.; Orton, Alice M.

2015-08-17

The U.S. Geological Survey Woods Hole Coastal and Marine Science Center has created a Data Library to organize, preserve, and make available the field, laboratory, and modeling data collected and processed by Woods Hole Coastal and Marine Science Center staff. This Data Library supports current research efforts by providing unique, historic datasets with accompanying metadata. The Woods Hole Coastal and Marine Science Center’s Data Library has custody of historic data and records that are still useful for research, and assists with preservation and distribution of marine science records and data in the course of scientific investigation and experimentation by researchers and staff at the science center.

Radiation effects and micromechanics of SiC/SiC composites (December 1, 1990--November 14, 1993) and modeling the mechanical behavior of SiC/SiC composites in fusion environments (November 15, 1993--November 14, 1996). Final report, December 1, 1990--November 14, 1996

International Nuclear Information System (INIS)

Ghoniem, N.M.

1997-01-01

The development of Silicon Carbide composite materials for structural applications in fusion energy systems is mainly motivated by the prospect that fusion power systems utilizing the material will have a much more favorable environmental impact. The research team at UCLA was the first to identify the potential advantages of SiC/SiC composite materials through early System Studies. Consequently, two three-year term grants have been awarded to the team, in order to focus on modeling the effects of irradiation on key properties that have been recognized by the community as fundamental to the successful development of the composite. Two main tasks, which are further subdivided into several subtasks each, have been pursued during the course of research during the period: December 1990 through November 1996. The first task deals with modeling the effects of irradiation on the dimensional stability of SiC. To achieve this goal, a substantial effort was launched for modeling the evolution of the microstructure under irradiation. Rate and Fokker-Planck theories have been advanced to model the complex multi-component system of SiC under irradiation. The effort has resulted in a deeper understanding of the interaction between displacement damage components, and transmutant helium gas atoms. Utilizing the methods of Molecular Dynamics (MD) and Monte Carlo (MC), the energetics of defects and the basic displacement mechanisms in SiC have been fully delineated. An advanced Fokker-Planck approach was formulated to determine the phase content and size distribution of damage microstructure in SiC. Finally, a rate theory model was developed and successfully applied to the experimental swelling data on SiC. In the second task, the authors investigated the mechanical behavior of SiC/SiC composites under the irradiation conditions of fusion reactors. The main focus of the second task has been on developing models for the micro-mechanics of cracks in the fiber reinforced matrix of the

Stress impedance effect of FeCoSiB/Cu/FeCoSiB sandwich layers on flexible substrate

International Nuclear Information System (INIS)

Peng, B.; Zhang, W.L.; Liu, J.D.; Zhang, W.X.

2011-01-01

FeCoSiB/Cu/FeCoSiB sandwich layers were deposited on flexible substrate to develop flexible stress/strain sensors. The influence of stress on the impedance of the multilayers is reported. The results show that the variation of the impedance increases with the increase in deflection of the free end of the cantilever. A relative change in impedance of 6.4% is obtained in the FeCoSiB(1.5 μm)/Cu(0.25 μm)/FeCoSiB(1.5 μm) sandwich layers at 1 MHz with deflection of 2 mm. The stress impedance effects are sensitive to the frequency of the current and the thickness of both FeCoSiB and Cu layers. The stress impedance effect increases with the increase in the thickness of FeCoSiB or Cu layers. The stress impedance effect increases slightly with the increase in frequency and decreases with the further increase in frequency, which can be understood by the stress and frequency-dependent permeability of magnetic films. - Research highlights: → We deposited FeCoSiB/Cu/FeCoSiB multilayer on flexible substrate. → We studied the stress impedance effect of FeCoSiB/Cu/FeCoSiB multilayer. → Stress impedance effect increases with thickness of both FeCoSiB and Cu layer.→ Stress impedance effect is dependent on current frequency. → Results are understood using stress and frequency-dependent permeability.

Microlevel mapping of coastal geomorphology and coastal resources of Rameswaram island, India: A remote sensing and GIS perspective

Digital Repository Service at National Institute of Oceanography (India)

Nobi, E.P.; Shivaprasad, A.; Karikalan, R.; Dilipan, E.; Thangaradjou, T.; Sivakumar, K.

Coastal areas are facing serious threats from both manmade and natural disturbances; coastal erosion, sea-level variation, and cyclones are the major factors that alter the coastal topography and coastal resources of the island ecosystems...

Study on the preparation of the SiCp/Al-20Si-3Cu functionally graded material using spray deposition

International Nuclear Information System (INIS)

Su, B.; Yan, H.G.; Chen, G.; Shi, J.L.; Chen, J.H.; Zeng, P.L.

2010-01-01

Research highlights: → The SiCp/Al-20Si-3Cu functionally gradient material (FGM) was successfully prepared via the spray deposition technique. → The SiCp/Al-20Si-3Cu functionally gradient material (FGM) was successfully prepared via the spray deposition technique. → In the experimental setup, the novel devices play an important role in adjusting the output of SiCp to prepare the FGM. → The experiment results reveal that the SiCp weight fraction of the as-deposited preform from the top to the bottom ranges almost continuously from 0% to 30%. → The fraction of SiC particles has no obvious influence on the phase constitutions of the SiCp/Al-20Si-3Cu FGM. - Abstract: The SiCp/Al-20Si-3Cu functionally gradient material (FGMs) was successfully prepared via the spray deposition technique accompanied with an automatic control system. The results reveal that the SiCp weight fraction of the as-deposited preform from the top to the bottom ranges almost continuously from 0% to 30%. The part with the higher SiCp weight fraction exhibits a relatively smaller density than that with the lower SiCp weight fraction. However, the microhardness and the porosity increase with the increasing SiCp weight fraction in the as-deposited preform. The X-ray diffraction results exhibit that the secondary phases in the regions with the different amount of SiC particles are the same such as Al 2 Cu and AlCuMg. The spray deposition technology is promising to produce a wide range of other FGMs.

Strained Si/SiGe MOS transistor model

Directory of Open Access Journals (Sweden)

Tatjana Pešić-Brđanin

2009-06-01

Full Text Available In this paper we describe a new model of surfacechannel strained-Si/SiGe MOSFET based on the extension of non-quasi-static (NQS circuit model previously derived for bulk-Si devices. Basic equations of the NQS model have been modified to account for the new physical parameters of strained-Si and relaxed-SiGe layers. From the comparisons with measurements, it is shown that a modified NQS MOS including steady-state self heating can accurately predict DC characteristics of Strained Silicon MOSFETs.

Effect of hydrogen on passivation quality of SiNx/Si-rich SiNx stacked layers deposited by catalytic chemical vapor deposition on c-Si wafers

International Nuclear Information System (INIS)

Thi, Trinh Cham; Koyama, Koichi; Ohdaira, Keisuke; Matsumura, Hideki

2015-01-01

We investigate the role of hydrogen content and fixed charges of catalytic chemical vapor deposited (Cat-CVD) SiN x /Si-rich SiN x stacked layers on the quality of crystalline silicon (c-Si) surface passivation. Calculated density of fixed charges is on the order of 10 12 cm −2 , which is high enough for effective field effect passivation. Hydrogen content in the films is also found to contribute significantly to improvement in passivation quality of the stacked layers. Furthermore, Si-rich SiN x films deposited with H 2 dilution show better passivation quality of SiN x /Si-rich SiN x stacked layers than those prepared without H 2 dilution. Effective minority carrier lifetime (τ eff ) in c-Si passivated by SiN x /Si-rich SiN x stacked layers is as high as 5.1 ms when H 2 is added during Si-rich SiN x deposition, which is much higher than the case of using Si-rich SiN x films prepared without H 2 dilution showing τ eff of 3.3 ms. - Highlights: • Passivation mechanism of Si-rich SiN x /SiN x stacked layers is investigated. • H atoms play important role in passivation quality of the stacked layer. • Addition of H 2 gas during Si-rich SiN x film deposition greatly enhances effective minority carrier lifetime (τ eff ). • For a Si-rich SiN x film with refractive index of 2.92, τ eff improves from 3.3 to 5.1 ms by H 2 addition

Processing, Microstructure, and Mechanical Properties of Si3N4/SiC Nanocomposites from Precursor Derived Ceramics

Science.gov (United States)

Strong, Kevin Thomas, Jr.

Polymer-derived ceramics (PDCs) provides a unique processing route to create Si3N4/SiC composites. Silazane precursor polyureasilazane (Ceraset PURS20) produce's an amorphous SiCN ceramic at temperatures of ~800 -- 1200 °C and crystallizes to a Si3N4/SiC nanocomposite at temperatures >1500 °C. A novel processing technique was developed where crosslinked polymers were heat-treated in a reactive NH3 atmosphere to control the stoichiometry of the pyrolyzed SiCN ceramic. Using this technique processing parameters were established to produce SiCN powders that resulted in nanocomposites with approximately 0, 5, 10, 20 and 30 vol. % SiC. Lu2O3 was added to these powders as a sintering aid and were densified using Hot Pressing and Field Assisted Sintering. The sintered nanocomposites resulted in microstructures with multiple-length scales. These length-scales included Si3N4 (0.1 -- 5 microm), SiC (10 -- 100 nm) and the intergranular grain boundary phase (<1 nm). Using a combination of SEM and TEM it was possible to quantify some of these microstructural features such as the size and location of the SiC. Hardness and fracture toughness testing was conducted to compared the room temperature mechanical properties of these resultant microstructures. This research was intended to develop robust processing approaches that can be used to control the nanostructures of Si3N4/SiC composites with significant structural features at multiple length scales. The control of their features and the investigation of their affect on the properties of composites can be used to simulate the affect of the structure on properties. These models can then be used to design optimal microstructures for specific applications.

Understanding influences in policy landscapes for sustainable coastal livelihoods

NARCIS (Netherlands)

Steenbergen, Dirk J.; Clifton, Julian; Visser, Leontine E.; Stacey, Natasha; McWilliam, Andrew

2017-01-01

Ensuring sustainability of livelihoods for communities residing in coastal environments of the Global South has gained considerable attention across policy making, practice and research fields. Livelihood enhancement programs commonly strategize around developing people's resilience by

Submarine groundwater discharge as an important nutrient source influencing nutrient structure in coastal water of Daya Bay, China

Science.gov (United States)

Wang, Xuejing; Li, Hailong; Zheng, Chunmiao; Yang, Jinzhong; Zhang, Yan; Zhang, Meng; Qi, Zhanhui; Xiao, Kai; Zhang, Xiaolang

2018-03-01

As an important nutrient source for coastal waters, submarine groundwater discharge (SGD) has long been largely ignored in Daya Bay, China. In this study, we estimate the fluxes of SGD and associated nutrients into this region using a 224Ra mass balance model and assess the contribution/importance of nutrients by SGD, benthic sediments, local rivers, and atmospheric deposition. The results of 224Ra mass balance show that the estimated SGD ranges from (2.76 ± 1.43) × 106 m3/d to (1.03 ± 0.53) × 107 m3/d with an average of (6.32 ± 2.42) × 106 m3/d, about 16 times the total discharge rate of local rivers. The nutrient loading from SGD is estimated to be (1.05-1.99) × 105 mol/d for NO3-N, (4.04-12.16) × 103 mol/d for DIP, and (3.54-11.35) × 105 mol/d for Si. Among these considered nutrient sources, we find that SGD is the primary source for Si and NO3-N, contributing 68% and 42% of all considered sources, respectively. The atmospheric NO3-N flux is comparable to that from SGD. The local rivers are the most important source for DIP, contributing 75% of all considered sources. SGD with high N:P ratio (NO3-N/DIP) of 37.0 delivers not only a large quantity of nutrients, but also changes nutrient structure in coastal water. Based on a DIP budget, primary productivity is evaluated to be 54-73 mg C/m2 d, in which SGD accounts for approximately 30% of total production. This study indicates that SGD is a key source of nutrients to coastal waters and may cause an obvious change of primary production and nutrient structure in Daya Bay.

Fast neutron detection at near-core location of a research reactor with a SiC detector

Science.gov (United States)

Wang, Lei; Jarrell, Josh; Xue, Sha; Tan, Chuting; Blue, Thomas; Cao, Lei R.

2018-04-01

The measurable charged-particle produced from the fast neutron interactions with the Si and C nucleuses can make a wide bandgap silicon carbide (SiC) sensor intrinsically sensitive to neutrons. The 4H-SiC Schottky detectors have been fabricated and tested at up to 500 °C, presenting only a slightly degraded energy resolution. The response spectrum of the SiC detectors were also obtained by exposing the detectors to external neutron beam irradiation and at a near-core location where gamma-ray field is intense. The fast neutron flux of these two locations are ∼ 4 . 8 × 104cm-2 ṡs-1 and ∼ 2 . 2 × 107cm-2 ṡs-1, respectively. At the external beam location, a Si detector was irradiated side-by-side with SiC detector to disjoin the neutron response from Si atoms. The contribution of gamma ray, neutron scattering, and charged-particles producing reactions in the SiC was discussed. The fast neutron detection efficiencies were determined to be 6 . 43 × 10-4 for the external fast neutron beam irradiation and 6 . 13 × 10-6 for the near-core fast neutron irradiation.

Porous SiC/SiC composites development for industrial application

International Nuclear Information System (INIS)

Maeta, S.; Hinoki, T.

2014-01-01

Silicon carbide (SiC) is promising structural materials in nuclear fields due to an excellent irradiation resistance and low activation characteristics. Conventional SiC fibers reinforced SiC matrix (SiC/SiC composites) fabricated by liquid phase sintering (LPS-SiC/SiC composites) have been required high cost and long processing time. And microstructure and mechanical property data of finally obtained LPS-SiC/SiC composites are easily scattered, because quality of the composites depend on personal skill. Thus, conventional LPS-SiC/SiC composites are inadequate for industrial use. In order to overcome these issues, the novel “porous SiC/SiC composites” have been developed by means of liquid phase sintering fabrication process. The composites consist of porous SiC matrix and SiC fibers without conventional carbon interfacial layer. The composites don’t have concerns of the degradation interfacial layer at the severe accident. Porous SiC/SiC composites preform was prepared with a thin sheet shape of SiC, sintering additives and carbon powder mixture by tape casting process which was adopted because of productive and high yielding rate fabrication process. The preform was stacked with SiC fibers and sintered in hot-press at the high temperature in argon environment. The sintered preform was decarburized obtain porous matrix structure by heat-treatment in air. Moreover, mechanical property data scattering of the obtained porous SiC/SiC composites decreased. In the flexural test, the porous SiC/SiC composites showed pseudo-ductile behavior with sufficient strength even after heat treatment at high temperature in air. From these conclusions, it was proven that porous SiC/SiC composites were reliable material at severe environment such as high temperature in air, by introducing tape casting fabrication process that could produce reproducible materials with low cost and simple way. Therefore development of porous SiC/SiC composites for industrial application was

Coastal risks in Sri-Lanka - GIS, scenario and modelling approaches

OpenAIRE

Garcin , Manuel; Desprats , Jean-François; Pedreros , Rodrigo; Fontaine , Mélanie; Sedan , Olivier; Lenotre , Nicole; Attanayake , Nishantha; De Silva , Udaya; Fernando , Starin; Siriwardana , Cher

2008-01-01

1 p.; International audience; The impact of the tsunami of December 26, 2004 in Sri Lanka clearly showed the importance of a thorough knowledge of coastal risks and of taking these into account in order to reduce their impacts. We present here a project funded by French Government (Ministère des Affaires Etrangères) and BRGM Research Division including both Sri Lankan and French institutions. The aims of this project are to implement an effective tool designed to reduce the impact of coastal ...

Biomorphous SiSiC/Al-Si ceramic composites manufactured by squeeze casting: microstructure and mechanical properties

Energy Technology Data Exchange (ETDEWEB)

Zollfrank, C.; Travitzky, N.; Sieber, H.; Greil, P. [Department of Materials Science, Glass and Ceramics, University of Erlangen-Nuernberg (Germany); Selchert, T. [Advanced Ceramics Group, Technical University of Hamburg-Harburg (Germany)

2005-08-01

SiSiC/Al-Si composites were fabricated by pressure-assisted infiltration of an Al-Si alloy into porous biocarbon preforms derived from the rattan palm. Al-Si alloy was found in the pore channels of the biomorphous SiSiC preform, whereas SiC and carbon were present in the struts. The formation of a detrimental Al{sub 4}C{sub 3}-phase was not observed in the composites. A bending strength of 200 MPa was measured. The fractured surfaces showed pull-out of the Al-alloy. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

The reduction of the change of secondary ions yield in the thin SiON/Si system

International Nuclear Information System (INIS)

Sameshima, J.; Yamamoto, H.; Hasegawa, T.; Nishina, T.; Nishitani, T.; Yoshikawa, K.; Karen, A.

2006-01-01

For the analyses of gate insulating materials of thin silicon oxy-nitride (SiON) and dielectric films, SIMS is one of the available tool along with TEM and ESCA, etc. Especially, to investigate the distribution of dopant in the thin films, SIMS is appreciably effective in these techniques because of its depth profiling capability and high sensitivity. One of the problem occurring in this SIMS measurement is the change of secondary ion yield at the interface as well as in the layers with different chemical composition. To solve this problem, some groups have researched the phenomenon for SiO 2 /Si interface [W. Vandervorst, T. Janssens, R. Loo, M. Caymax, I. Peytier, R. Lindsay, J. Fruhauf, A. Bergmaier, G. Dollinger, Appl. Surf. Sci. 203-204 (2003) 371-376; S. Hayashi, K.Yanagihara, Appl. Surf. Sci. 203-204 (2003) 339-342; M. Barozzi, D. Giubertoni, M.Anderle, M. Bersani, Appl. Surf. Sci. 231-232 (2004) 632-635; T.H. Buyuklimanli, J.W. Marino, S.W. Novak, Appl. Surf. Sci. 231-232 (2004) 636-639]. In the present study, profiles of boron and matrix elements in the Si/SiON layers on Si substrate have been investigated. The sensitivity change of Si and B profiles in SiON layer become smaller by using oxygen flood than those without oxygen flood for both O 2 + and Cs + beam. At the range of 0-25 at.% of N composition, 11 B dosimetry in SiON layer implanted through amorphous Si depends on N composition. This trend could be caused by the sensitivity change of 11 B, or it indicates real 11 B concentration change in SiON lyaer. N areal density determined by Cs + SIMS with oxygen flooding also shows linear relationship with N composition estimated by XPS

Coastal Erosion Armoring 2005

Data.gov (United States)

California Natural Resource Agency — Coastal armoring along the coast of California, created to provide a database of all existing coastal armoring based on data available at the time of creation....

Reaction mechanisms at 4H-SiC/SiO2 interface during wet SiC oxidation

Science.gov (United States)

Akiyama, Toru; Hori, Shinsuke; Nakamura, Kohji; Ito, Tomonori; Kageshima, Hiroyuki; Uematsu, Masashi; Shiraishi, Kenji

2018-04-01

The reaction processes at the interface between SiC with 4H structure (4H-SiC) and SiO2 during wet oxidation are investigated by electronic structure calculations within the density functional theory. Our calculations for 4H-SiC/SiO2 interfaces with various orientations demonstrate characteristic features of the reaction depending on the crystal orientation of SiC: On the Si-face, the H2O molecule is stable in SiO2 and hardly reacts with the SiC substrate, while the O atom of H2O can form Si-O bonds at the C-face interface. Two OH groups are found to be at least necessary for forming new Si-O bonds at the Si-face interface, indicating that the oxidation rate on the Si-face is very low compared with that on the C-face. On the other hand, both the H2O molecule and the OH group are incorporated into the C-face interface, and the energy barrier for OH is similar to that for H2O. By comparing the calculated energy barriers for these reactants with the activation energies of oxide growth rate, we suggest the orientation-dependent rate-limiting processes during wet SiC oxidation.

Total Ionizing Dose Effects of Si Vertical Diffused MOSFET with SiO2 and Si3N4/SiO2 Gate Dielectrics

Directory of Open Access Journals (Sweden)

Jiongjiong Mo

2017-01-01

Full Text Available The total ionizing dose irradiation effects are investigated in Si vertical diffused MOSFETs (VDMOSs with different gate dielectrics including single SiO2 layer and double Si3N4/SiO2 layer. Radiation-induced holes trapping is greater for single SiO2 layer than for double Si3N4/SiO2 layer. Dielectric oxidation temperature dependent TID effects are also studied. Holes trapping induced negative threshold voltage shift is smaller for SiO2 at lower oxidation temperature. Gate bias during irradiation leads to different VTH shift for different gate dielectrics. Single SiO2 layer shows the worst negative VTH at VG=0 V, while double Si3N4/SiO2 shows negative VTH shift at VG=-5 V, positive VTH shift at VG=10 V, and negligible VTH shift at VG=0 V.

Elements of a coastal ocean forecasting system for India

Digital Repository Service at National Institute of Oceanography (India)

Shetye, S.R.; Radhakrishnan, K.

After about four decades of investment in infrastructure for ocean research, an appropriate initiative for India now would be to build a coastal ocean forecasting system to support the country's myriad activities in its Exclusive Economic Zone...

Electron Spin Coherence Times in Si/SiGe Quantum Dots

Science.gov (United States)

Jock, R. M.; He, Jianhua; Tyryshkin, A. M.; Lyon, S. A.; Lee, C.-H.; Huang, S.-H.; Liu, C. W.

2014-03-01

Single electron spin states in silicon have shown a great deal of promise as qubits due to their long spin relaxation (T1) and coherence (T2) times. Recent results exhibit a T2 of 250 us for electrons confined in Si/SiGe quantum dots at 350 mK. These experiments used conventional X-band (10 GHz) pulsed Electron Spin Resonance on a large area (3.5 mm x 20 mm), dual-gated, undoped Si/SiGe heterostructure quantum dots. These dots are induced in a natural Si quantum well by e-beam defined gates having a lithographic radius of 150 nm and pitch of 700 nm. The relatively large size of these dots led to closely spaced energy levels and long T2's could only be measured at sub-Kelvin temperatures. At 2K confined electrons displayed a 3 us T2, which is comparable to that of 2D electrons at that temperature. Decreasing the quantum dot size increases the electron confinement and reduces the effects of valley-splitting and spin-orbit coupling on the electron spin coherence times. We will report results on dots with 80 nm lithographic radii and a 375 nm pitch. This device displays an extended electron coherence time of 30 us at 2K, suggesting tighter confinement of electrons. Further measurements at lower temperatures are in progress. This work was supported in part by NSF through the Materials World Network program (DMR-1107606) and the Princeton MRSEC (DMR-0819860), and in part by the U.S. Army Research Office (W911NF-13-1-0179).

Sea Extremes: Integrated impact assessment in coastal climate adaptation

DEFF Research Database (Denmark)

Sørensen, Carlo Sass; Knudsen, Per; Broge, Niels

2016-01-01

protection measures, topography, and infrastructure to provide a more complete picture of the water-related impact from climate change at an exposed coastal location. Results show that future sea extremes evaluated from extreme value statistics may, indeed, have a large impact. The integrated effects from......We investigate effects of sea level rise and a change in precipitation pattern on coastal flooding hazards. Historic and present in situ and satellite data of water and groundwater levels, precipitation, vertical ground motion, geology,and geotechnical soil properties are combined with flood...... research advances and projections for the future are updated....

Electrically modulated lateral photovoltage in μc-SiOx:H/a-Si:H/c-Si p-i-n structure at low temperatures

Energy Technology Data Exchange (ETDEWEB)

Liu, Jihong; Qiao, Shuang, E-mail: sqiao@hbu.edu.cn; Wang, Jianglong; Wang, Shufang, E-mail: sfwang@hbu.edu.cn; Fu, Guangsheng

2017-04-15

Graphical abstract: In this paper, the temperature dependence of the LPE has been experimentally studied under illumination of different lasers ranging from visible to infrared for the μc-SiOx:H/a-Si:H/c-Si p-i-n structure. It was found that the position sensitivity increases nearly linearly with wavelength from 405 nm to 980 nm in the whole temperature range, and the saturated position sensitivity decreased quickly from 32.4 mV/mm to a very low value of 1.26 mV/mm and the nonlinearity improved from 7.01% to 3.54% with temperature decreasing from 296 K to 80 K for 532 nm laser illumination. By comparing the experiment results of μc-SiOx:H/a-Si:H/c-Si and ITO/c-Si, it is suggest that the position sensitivity was mainly determined by the temperature-dependent SB and the nonlinearity was directly related to the decreased resistivity of conductive layer. When an external bias voltage was applied, the LPE improved greatly and the position sensitivity of 361.35 mV/mm under illumination of 80 mW at 80 K is 286.7 times as large as that without biased voltage. More importantly, both the position sensitivity and the nonlinearity were independent of temperature again, which can be ascribed to the large constant transmission probability and diffusion length induced by the greatly increased SB. Our research provides an essential insight on the bias voltage-modulated LPE at different temperatures, and this temperature-independent greatly improved LPE is thought to be very useful for developing novel photoelectric devices. - Highlights: • The LPE is proportional to the laser wavelength in the whole temperature range. • The LPE decreases gradually with decreasing temperature from 296 K to 80 K. • Nonlinearity of the LPV curve improves a little with decreasing temperature. • The LPE improves dramatically and is independent of temperature with the aid of a bias voltage. - Abstract: The lateral photovoltaic effect (LPE) in μc-SiOx:H/a-Si:H/c-Si p-i-n structure is studied

Nanocatalytic growth of Si nanowires from Ni silicate coated SiC nanoparticles on Si solar cell.

Science.gov (United States)

Parida, Bhaskar; Choi, Jaeho; Ji, Hyung Yong; Park, Seungil; Lim, Gyoungho; Kim, Keunjoo

2013-09-01

We investigated the nanocatalytic growth of Si nanowires on the microtextured surface of crystalline Si solar cell. 3C-SiC nanoparticles have been used as the base for formation of Ni silicate layer in a catalytic reaction with the Si melt under H2 atmosphere at an annealing temperature of 1100 degrees C. The 10-nm thick Ni film was deposited after the SiC nanoparticles were coated on the microtextured surface of the Si solar cell by electron-beam evaporation. SiC nanoparticles form a eutectic alloy surface of Ni silicate and provide the base for Si supersaturation as well as the Ni-Si alloy layer on Si substrate surface. This bottom reaction mode for the solid-liquid-solid growth mechanism using a SiC nanoparticle base provides more stable growth of nanowires than the top reaction mode growth mechanism in the absence of SiC nanoparticles. Thermally excited Ni nanoparticle forms the eutectic alloy and provides collectively excited electrons at the alloy surface, which reduces the activation energy of the nanocatalytic reaction for formation of nanowires.

Climate Change Impacts on the Mediterranean Coastal Zones

International Nuclear Information System (INIS)

Brochier, F.; Ramieri, E.

2001-04-01

The main objective of this paper is to highlight the potential impacts of changes in climatic conditions and in related variables, which could affect coastal areas, as well as to identify potential response measures which could reduce the vulnerability of coastal systems and enhance their adaptability. Attention will be focused on the Mediterranean basin which is in the climate change context, a zone of great interest and of recent concern at the world scale by some features: strong ocean-atmosphere-land interactions; contrast between the small size of the sea and its significant role in the global climate system; possibility to use it at a scaled down model for the monitoring of environmental and climate evolution; critical environmental conditions of some areas and high human pressure; and strong geographical, socio-economic and climatic contrasts. The first section provides an introduction to the climate change issue, the past trends and the projections of future climate at the global scale. The second section presents the main features of the Mediterranean basin and some relevant regional projections of future climatic variables. The third section focuses on the main likely impacts on the Mediterranean coasts. Different coastal systems - such as islands, deltas, estuaries, coastal wetlands and coastal cities - and different climate change impacts - such as inundation, increased flooding, salinisation, salt water intrusion, desertification, and increased erosion - are addressed in this section. Finally the last section brings some conclusions and identify some strategies of adaptations and directions for future research aimed at improving our ability to predict and assess the local impacts of climate change in the region

Oxide Structure Dependence of SiO2/SiOx/3C-SiC/n-Type Si Nonvolatile Resistive Memory on Memory Operation Characteristics

Science.gov (United States)

Yamaguchi, Yuichiro; Shouji, Masatsugu; Suda, Yoshiyuki

2012-11-01

We have investigated the dependence of the oxide layer structure of our previously proposed metal/SiO2/SiOx/3C-SiC/n-Si/metal metal-insulator-semiconductor (MIS) resistive memory device on the memory operation characteristics. The current-voltage (I-V) measurement and X-ray photoemission spectroscopy results suggest that SiOx defect states mainly caused by the oxidation of 3C-SiC at temperatures below 1000 °C are related to the hysteresis memory behavior in the I-V curve. By restricting the SiOx interface region, the number of switching cycles and the on/off current ratio are more enhanced. Compared with a memory device formed by one-step or two-step oxidation of 3C-SiC, a memory device formed by one-step oxidation of Si/3C-SiC exhibits a more restrictive SiOx interface with a more definitive SiO2 layer and higher memory performances for both the endurance switching cycle and on/off current ratio.

Challenges of Tsunami Disaster and Extreme climate Events Along Coastal Region in Asia-Pacific

Science.gov (United States)

Chaudhari, S.

2017-12-01

South Asia is more vulnerable to Geo disasters and impacts of climate changes in recent years. On 26 December 2004 massive waves triggered by an earthquake surged into coastal communities in Asia and East Africa with devastating force. Hitting Indonesia, Sri Lanka , Thailand and India hardest, the deadly waves swept more than 200 000 people to their deaths. Also in an another extreme climate change phenomenon during 2005 - 2006,causing heavy rains and flooding situation in the South Asia - Europe and Pacific region ,more than 100 million population in these regions are witnessing the social- economical and ecological risks and impacts due to climate changes and Geohazards. For mitigating geo-disasters, marine hazards and rehabilitation during post tsunami period, scientific knowledge is needed, requiring experienced research communities who can train the local population during tsunami rehabilitation. Several civil society institutions jointly started the initiatives on the problem identifications in management of risks in geo-disasters, tsunami rehabilitation ,Vulnerability and risk assessments for Geohazards etc., to investigate problems related to social-economic and ecological risks and management issues resulting from the December tsunami and Geo- disaster, to aid mitigation planning in affected areas and to educate scientists and local populations to form a basis for sustainable and economic solutions. The poster aims to assess the potential risk and hazard , technical issues, problems and damage arising from Tsunami in the Asia-pacific region in coastal geology, coastal ecosystems and coastal environmental systems . This poster deals with the status and issues of interactions between Human and Ocean Systems, Geo-risks, marine risks along coastal region of Asia- Pacific and also human influence on the earth system . The poster presentation focuses on capacity building of the local population, scientists and researchers for integration of human and ocean

Analyzing potential effects of migration on coastal resource conservation in Southeastern Ghana.

Science.gov (United States)

Goldbach, Carina; Schlüter, Achim; Fujitani, Marie

2018-03-01

Coastal areas are under increasing pressure from rapid human population growth, yet empirical research on the effect of migration on coastal and marine resources is scarce. We contribute to this understudied literature by conducting an original household survey in a coastal region of Southeastern Ghana. This study employs two proxies for pro-environmental behavior that have not, to our knowledge, been used in the context of coastal migration, to explicitly compare migrant and non-migrant populations. Environmental attitudes toward coastal resources and individual extraction behavior in common-pool resource (CPR) experiments have shown broad relevance in the literature to understand natural resource decision making. We found that migrants in general did not differ significantly from non-migrants in relation to their environmental attitudes or their extraction behavior in the CPR game. However, when focusing on migrant fishers only, results suggested that this subgroup was less concerned about the utilization of coastal resources than non-migrant fishers and behaved less cooperatively in the CPR experiment. These findings, though, held true only for the subgroup of fishers, and could not be found for other occupational groups. Therefore, we conclude that migrants do not per se value coastal resources less or cooperate less in CPR situations, but that socioeconomic characteristics, and particularly their occupational status and their relation to the resource, matter. Copyright © 2018 Elsevier Ltd. All rights reserved.

Interfacial characterization of CVI-SiC/SiC composites

International Nuclear Information System (INIS)

Yang, W.; Kohyama, A.; Noda, T.; Katoh, Y.; Hinoki, T.; Araki, H.; Yu, J.

2002-01-01

The mechanical properties of the interfaces of two families of chemical vapor infiltration SiC/SiC composites, advanced Tyranno-SA and Hi-Nicalon fibers reinforced SiC/SiC composites with various carbon and SiC/C interlayers, were investigated by single fiber push-out/push-back tests. Interfacial debonding and fibers sliding mainly occurred adjacent to the first carbon layer on the fibers. The interfacial debonding strengths and frictional stresses for both Tyranno-SA/SiC and Hi-Nicalon/SiC composites were correlated with the first carbon layer thickness. Tyranno-SA/SiC composites exhibited much larger interfacial frictional stresses compared to Hi-Nicalon/SiC composites. This was assumed to be mainly contributed by the rather rough surface of the Tyranno-SA fiber

Coastal Adaptation to Climate Change. Can the IPCC Technical Guidelines be applied?

International Nuclear Information System (INIS)

Klein, R.J.T.; Nicholls, R.J.; Mimura, Nobuo

1999-01-01

This paper evaluates the IPCC Technical Guidelines for Assessing Climate Change Impacts and Adaptations with respect to the guidance offered for coastal-adaptation assessment. It appears that the IPCC Technical Guidelines focus strongly on implementation. This paper uses both conceptual, and empirical information is used in this paper to show that coastal adaptation embraces more than selecting one of the 'technical' options to respond to sea-level rise (retreat, accommodate or protect). Coastal adaptation is a more complex and iterative process with a series of policy cycles. To be effective, an expanded adaptation framework involving four steps is suggested, including (1) information collection and awareness raising; (2) planning and design; (3) implementation, and (4) monitoring and evaluation. The incomplete coverage of these four steps in existing coastal-adaptation assessments constrains the development of adaptation strategies that are supported by the relevant actors and integrated into existing management. Researchers and policy-makers are recommended to work together to establish a framework for adaptation that is integrated within current coastal management processes and practices and takes a broader view on the subject. 46 refs

Nanocrystalline SiC and Ti₃SiC₂ Alloys for Reactor Materials: Annual Report

Energy Technology Data Exchange (ETDEWEB)

Henager, Charles H. [pnnl; Alvine, Kyle J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Roosendaal, Timothy J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Shin, Yongsoon [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Nguyen, Ba Nghiep; Borlaug, Brennan A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Jiang, Weilin [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Arreguin, Shelly A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2015-01-15

A new dual-phase nanocomposite of Ti₃SiC₂/SiC is being synthesized using preceramic polymers, ceramic powders, and carbon nanotubes (CNTs) designed to be suitable for advanced nuclear reactors and perhaps as fuel cladding. The material is being designed to have superior fracture toughness compared to SiC, adequate thermal conductivity, and higher density than SiC/SiC composites. This annual report summarizes the progress towards this goal and reports progress in understanding certain aspects of the material behavior but some shortcomings in achieving full density or in achieving adequate incorporation of CNTs. The measured thermal conductivity is adequate and falls into an expected range based on SiC and Ti₃SiC₂. Part of this study makes an initial assessment for Ti₃SiC₂ as a barrier to fission product transport. Ion implantation was used to introduce fission product surrogates (Ag and Cs) and a noble metal (Au) in Ti₃SiC₂, SiC, and a synthesized at PNNL. The experimental results indicate that the implanted Ag in SiC is immobile up to the highest temperature (1273 K) applied in this study; in contrast, significant out-diffusion of both Ag and Au in MAX phase Ti₃SiC₂ occurs during ion implantation at 873 K. Cs in Ti₃SiC₂ is found to diffuse during post-irradiation annealing at 973 K, and noticeable Cs release from the sample is observed. This study may suggest caution in using Ti₃SiC₂ as a fuel cladding material for advanced nuclear reactors operating at very high temperatures. Progress is reported in thermal conductivity modeling of SiC-based materials that is relevant to this research, as is progress in modeling the effects of CNTs on fracture strength of SiC-based materials.

Low dose irradiation performance of SiC interphase SiC/SiC composites

International Nuclear Information System (INIS)

Snead, L.L.; Lowden, R.A.; Strizak, J.; More, K.L.; Eatherly, W.S.; Bailey, J.; Williams, A.M.; Osborne, M.C.; Shinavski, R.J.

1998-01-01

Reduced oxygen Hi-Nicalon fiber reinforced composite SiC materials were densified with a chemically vapor infiltrated (CVI) silicon carbide (SiC) matrix and interphases of either 'porous' SiC or multilayer SiC and irradiated to a neutron fluence of 1.1 x 10 25 n m -2 (E>0.1 MeV) in the temperature range of 260 to 1060 C. The unirradiated properties of these composites are superior to previously studied ceramic grade Nicalon fiber reinforced/carbon interphase materials. Negligible reduction in the macroscopic matrix microcracking stress was observed after irradiation for the multilayer SiC interphase material and a slight reduction in matrix microcracking stress was observed for the composite with porous SiC interphase. The reduction in strength for the porous SiC interfacial material is greatest for the highest irradiation temperature. The ultimate fracture stress (in four point bending) following irradiation for the multilayer SiC and porous SiC interphase materials was reduced by 15% and 30%, respectively, which is an improvement over the 40% reduction suffered by irradiated ceramic grade Nicalon fiber materials fabricated in a similar fashion, though with a carbon interphase. The degradation of the mechanical properties of these composites is analyzed by comparison with the irradiation behavior of bare Hi-Nicalon fiber and Morton chemically vapor deposited (CVD) SiC. It is concluded that the degradation of these composites, as with the previous generation ceramic grade Nicalon fiber materials, is dominated by interfacial effects, though the overall degradation of fiber and hence composite is reduced for the newer low-oxygen fiber. (orig.)

Carbon redistribution and precipitation in high temperature ion-implanted strained Si/SiGe/Si multi-layered structures

DEFF Research Database (Denmark)

Gaiduk, Peter; Hansen, John Lundsgaard; Nylandsted Larsen, Arne

2014-01-01

Graphical abstract Carbon depth profiles after high temperature implantation in strained Si/SiGe/Si multilayered system and induced structural defects.......Graphical abstract Carbon depth profiles after high temperature implantation in strained Si/SiGe/Si multilayered system and induced structural defects....

Bataan Coastal Resource Management Programs: Environmental, Socio-Economic, and Implementation Issues from Stakeholders’ Views

Directory of Open Access Journals (Sweden)

Alvin B. Cervania

2018-02-01

Full Text Available A study on the status of Bataan’s coastal zones, and the issues on the province’s coastal resource management (CRM programs under an integrated framework was commissioned by the Department of Science and Technology-Region III in the Philippines. Twenty-eight representative coastal villages and 11 water testing sites served as study areas. The research participants totalled to 1,300. Focused group discussions, survey and interviews, laboratory testing, documentary analysis, and literature review were used in the data gathering. It was concluded that the province’s coastal zones are in a disturbed state, which has negative implications to its already subsistent coastal population and important coastal economic activities. The province’s CRM projects have been arbitrary and intermittent. There are too few conservation initiatives due to scarcity of baseline data necessary for more methodical CRM programs. There is poor grassroots level involvement in CRM decision-making processes as well which clearly defeats the essence of integrated coastal management. A coordinated effort to strengthen stakeholder participation in critical CRM stages, and to conduct more comprehensive profilings and assessments of the province’s coastal environment involving the government, academics, and scientists are recommended to substantiate stakeholder involvement and increase the quality of data for CRM projects.

Residual Stress Measurement of SiC tile/Al7075 Hybrid Composites by Neutron Diffraction

Energy Technology Data Exchange (ETDEWEB)

Park, Jong Bok; Lee, Jun Ho; Hong, Soon Hyung; Ryu, Ho Jin [KAIST, Daejeon (Korea, Republic of); Lee, Sang Bok; Lee, Sang Kwan [Korea Institute of Materials Science, Changwon (Korea, Republic of); Muslihd, M. Rifai [Center for Advanced Materials Science and Technology, Tangerang (India)

2016-05-15

In this research, SiC which has low density, high compressive strength, and high elastic modulus was used to fabricate the armor plate. In addition, Al which has low density and high toughness was used for a metal matrix of the composites. If two materials are combined, the composite can be effective materials for light weight armor applications. However, the existence of a large difference in coefficients of thermal expansion (CTE) between SiC and Al matrix, SiC/Al composites can have residual stresses while cooled in the fabrication process. Previous research reported that residual stresses in the composites or microstructures have an effect on the fatigue life and their mechanical properties. Some researchers reported about the residual stresses in the SiCp/Al metal matrix composites by numerical simulation systems, X-ray diffraction, and destructive methods. In order to analyze the residual stress of SiC/Al composites, the neutron diffraction as the non-destructive method was performed in this research. The 50 vol.% SiC{sub p}/Al7075 composites and SiC tile inserted 50 vol.% SiC{sub p}/Al7075 hybrid composites were measured to analyze the residual stress of Al (111) and SiC (111). Both samples had the tensile residual stresses in the Al (111) and the compressive residual stresses in the SiC (111) due to the difference in CTE.

High-dose MeV electron irradiation of Si-SiO2 structures implanted with high doses Si+

Science.gov (United States)

Kaschieva, S.; Angelov, Ch; Dmitriev, S. N.

2018-03-01

The influence was studied of 22-MeV electron irradiation on Si-SiO2 structures implanted with high-fluence Si+ ions. Our earlier works demonstrated that Si redistribution is observed in Si+-ion-implanted Si-SiO2 structures (after MeV electron irradiation) only in the case when ion implantation is carried out with a higher fluence (1016 cm-2). We focused our attention on the interaction of high-dose MeV electron irradiation (6.0×1016 cm-2) with n-Si-SiO2 structures implanted with Si+ ions (fluence 5.4×1016 cm-2 of the same order magnitude). The redistribution of both oxygen and silicon atoms in the implanted Si-SiO2 samples after MeV electron irradiation was studied by Rutherford back-scattering (RBS) spectroscopy in combination with a channeling technique (RBS/C). Our results demonstrated that the redistribution of oxygen and silicon atoms in the implanted samples reaches saturation after these high doses of MeV electron irradiation. The transformation of amorphous SiO2 surface into crystalline Si nanostructures (after MeV electron irradiation) was evidenced by atomic force microscopy (AFM). Silicon nanocrystals are formed on the SiO2 surface after MeV electron irradiation. The shape and number of the Si nanocrystals on the SiO2 surface depend on the MeV electron irradiation, while their size increases with the dose. The mean Si nanocrystals height is 16-20 nm after irradiation with MeV electrons at the dose of 6.0×1016 cm-2.

Applications of Si/SiGe heterostructures to CMOS devices

International Nuclear Information System (INIS)

Sidek, R.M.

1999-03-01

For more than two decades, advances in MOSFETs used in CMOS VLSI applications have been made through scaling to ever smaller dimensions for higher packing density, faster circuit speed and lower power dissipation. As scaling now approaches nanometer regime, the challenge for further scaling becomes greater in terms of technology as well as device reliability. This work presents an alternative approach whereby non-selectively grown Si/SiGe heterostructure system is used to improve device performance or to relax the technological challenge. SiGe is considered to be of great potential because of its promising properties and its compatibility with Si, the present mainstream material in microelectronics. The advantages of introducing strained SiGe in CMOS technology are examined through two types of device structure. A novel structure has been fabricated in which strained SiGe is incorporated in the source/drain of P-MOSFETs. Several advantages of the Si/SiGe source/drain P-MOSFETs over Si devices are experimentally, demonstrated for the first time. These include reduction in off-state leakage and punchthrough susceptibility, degradation of parasitic bipolar transistor (PBT) action, suppression of CMOS latchup and suppression of PBT-induced breakdown. The improvements due to the Si/SiGe heterojunction are supported by numerical simulations. The second device structure makes use of Si/SiGe heterostructure as a buried channel to enhance the hole mobility of P-MOSFETs. The increase in the hole mobility will benefit the circuit speed and device packing density. Novel fabrication processes have been developed to integrate non-selective Si/SiGe MBE layers into self-aligned PMOS and CMOS processes based on Si substrate. Low temperature processes have been employed including the use of low-pressure chemical vapor deposition oxide and plasma anodic oxide. Low field mobilities, μ 0 are extracted from the transfer characteristics, Id-Vg of SiGe channel P-MOSFETs with various Ge

U.S. Geological Survey (USGS) Western Region: Coastal and Ocean Science

Science.gov (United States)

Kinsinger, Anne E.

2009-01-01

USGS Western Region Coastal and Ocean Science is interdisciplinary, collaborative, and integrates expertise from all USGS Disciplines, and ten of its major Science Centers, in Alaska, Hawai'i, California, Washington, and Oregon. The scientific talent, laboratories, and research vessels in the Western Region and across the Nation, strategically position the USGS to address broad geographic and oceanographic research topics. USGS information products inform resource managers and policy makers who must balance conservation mandates with increasing demands for resources that sustain the Nation's economy. This fact sheet describes but a few examples of the breadth of USGS science conducted in coastal, nearshore, and ocean environments along our Nation's West Coast and Pacific Islands.

Microstructure and strain distribution in freestanding Si membrane strained by Si{sub x}N{sub y} deposition

Energy Technology Data Exchange (ETDEWEB)

Gao Hongye, E-mail: qgaohongye@msn.com [Faculty of Engineering Sciences, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580 (Japan); Ikeda, Ken-ichi; Hata, Satoshi; Nakashima, Hideharu [Faculty of Engineering Sciences, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580 (Japan); Wang Dong; Nakashima, Hiroshi [Art, Science and Technology Center for Cooperative Research, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580 (Japan)

2010-09-25

Research highlights: {yields} Strain is introduced by deposition of amorphous Si{sub x}N{sub y} to improve the carrier mobility for a relatively large-size freestanding semiconductor film, which can be used for the fabrication of relatively large devices such like a bipolar junction transistor. However, standard Raman spectroscopy and X-ray diffraction cannot provide sufficient lateral resolution to the strain in a relatively long (x {mu}m in length) and thin (x nm in thickness) freestanding semiconductor film. {yields} In present research, strain in a bridge-shaped freestanding Si membrane (FSSM) was measured by convergent-beam electron diffraction (CBED) and finite element method (FEM). Compressive strain distribution was shown in three dimensions (3D) in FSSM, where no threading dislocation or stacking fault was found. Relaxation of the strain in FSSM in 3D was discussed based on a comparison of the strain magnitudes in FSSM as measured by CBED and FEM. - Abstract: Strain in a bridge-shaped freestanding Si membrane (FSSM) induced by depositing an amorphous Si{sub x}N{sub y} layer was measured by convergent-beam electron diffraction (CBED). CBED results show that the strain magnitude depends negatively on the FSSM thickness. FEM is a supplement of the result of CBED due to the relaxation of TEM samples during fabricating. The FEM analysis results ascertain the strain property in three dimensions, and show that the strain magnitude depends negatively on the length of FSSM, and the magnitude of the compressive strain in FSSM increases as the position is closer to the upper Si/Si{sub x}N{sub y} interface.

Investigation on the variation of channel resistance and contact resistance of SiZnSnO semiconductor depending on Si contents using transmission line method

Science.gov (United States)

Lee, Byeong Hyeon; Han, Sangmin; Lee, Sang Yeol

2018-01-01

Amorphous silicon-zinc-tin-oxide (a-SZTO) thin film transistors (TFTs) have been fabricated depending on the silicon ratio in channel layers. The a-SZTO TFT exhibited high electrical properties, such as high mobility of 23 cm2 V-1 s-1, subthreshold swing of 0.74 V/decade and ION/OFF of 2.8 × 108, despite of the addition of Si suppressor. The physical mechanism on the change of the sheet resistance and the contact resistance in a-SZTO TFT has been investigated and proposed closely related with the Si ratio. Both resistances were increased as increasing Si ratio, which clearly indicated that the role of Si is a carrier suppressor directly leading to the increase of channel and contact resistances. To explain the role of Si as a carrier suppressor, the conduction band offset mechanism has been also proposed depending on the change of carrier concentration in channel layer and at the interface between electrode and channel layer. 2007.01-2011.12 Senior Researcher at korea institute of science and technology (KOREA). 2008.01-2011.12 Professor at University of Science and Technology (KOREA). 1995.01-2007.12 Professor at Yonsei University (KOREA). 2002.01-2003.12 Inviting Researcher at Los Alamos National Lab (USA). 1993.01-1995.12 Senior Researcher at Electronics and Telecommunications Research Institute (KOREA). 1992.01-1993.01 Research Associate at State University of New York at Buffalo (USA).

Irradiation effect on Nite-SiC/SiC composites

International Nuclear Information System (INIS)

Hinoki, T.; Choi, Y.B.; Kohyama, A.; Ozawa, K.

2007-01-01

Full text of publication follows: Silicon carbide (SiC) and SiC composites are significantly attractive materials for nuclear application in particular due to exceptional low radioactivity, excellent high temperature mechanical properties and chemical stability. Despite of the excellent potential of SiC/SiC composites, the prospect of industrialization has not been clear mainly due to the low productivity and the high material cost. Chemical vapor infiltration (CVI) method can produce the excellent SiC/SiC composites with highly crystalline and excellent mechanical properties. It has been reported that the high purity SiC/SiC composites reinforced with highly crystalline fibers and fabricated by CVI method is very stable to neutron irradiation. However the production cost is high and it is difficult to fabricate thick and dense composites by CVI method. The novel processing called Nano-powder Infiltration and Transient Eutectic Phase (NITE) Processing has been developed based on the liquid phase sintering (LPS) process modification. The NITE processing can achieve both the excellent material quality and the low processing cost. The productivity of the processing is also excellent, and various kinds of shape and size of SiC/SiC composites can be produced by the NITE processing. The NITE processing can form highly crystalline matrix, which is requirement for nuclear application. The objective of this work is to understand irradiation effect of the NITESiC/SiC composites. The SiC/SiC composites used were reinforced with high purity SiC fibers, Tyranno TM SA and fabricated by the NITE method. The NITE-SiC/SiC composite bars and reference monolithic SiC bars fabricated by CVI and NITE were irradiated at up to 1.0 dpa and 600-1000 deg. C at JMTR, Japan. Mechanical properties of non-irradiated and irradiated NITESiC/ SiC composites bars were evaluated by tensile tests. Monolithic SiC bars were evaluated by flexural tests. The fracture surface was examined by SEM. Ultimate

Kepuasan Pengunjung Terhadap Kualitas Makanan Lendot Di Kawasan Wisata Taman Kota Coastal Area Kabupaten Karimun

OpenAIRE

", Hanisah; Achnes, Syofia

2017-01-01

The satisfaction is compatibility of product accepted and expectation of product. The research was conducted to determine the satisfaction of visitors to the quality of food lendot in The Tourist Area Of The City Park Coastal Area Karimun Regency. The research method used is quantitative approach. The sample technique used is accidental sampling. Samples taken as many as 40 respondents who consume a lendot in the Kawasan Wisata Taman Kota Coastal Area Kabupaten Karimun, where taken into the r...

Stability analysis of SiO2/SiC multilayer coatings

International Nuclear Information System (INIS)

Fu Zhiqiang; Jean-Charles, R.

2006-01-01

The stability behaviours of SiC coatings and SiO 2 /SiC coatings in helium with little impurities are studied by HSC Chemistry 4.1, the software for analysis of Chemical reaction and equilibrium in multi-component complex system. It is found that in helium with a low partial pressure of oxidative impurities under different total pressure, the key influence factor controlling T cp of SiC depends is the partial pressure of oxidative impurities; T cp of SiC increases with the partial pressure of oxidative impurities. In helium with a low partial pressure of different impurities, the key influence factor of T cs of SiO 2 are both the partial pressure of impurities and the amount of impurities for l mol SiO 2 ; T cs of SiO 2 increases with the partial pressure of oxidative impurities at the same amount of the impurities for 1 mol SiO 2 while it decreases with the amount of the impurities for 1 mm SiO 2 at the same partial pressure of the impurities. The influence of other impurities on T cp of SiC in He-O 2 is studied and it is found that CO 2 , H 2 O and N-2 increase T cp of SiC in He-O 2 while H 2 , CO and CH 4 decrease T cp of SiC He-O 2 . When there exist both oxidative impurities and reductive impurities, their effect on T cs of SiO 2 can be suppressed by the other. In HTR-10 operation atmosphere, SiO 2 /SiC coatings can keep stable status at higher temperature than SiC coatings, so SiO 2 /SiC coatings is more suitable to improve the oxidation resistance of graphite in HTR-10 operation atmosphere compared with SiC coatings. (authors)

Si-O-Si bond-angle distribution in vitreous silica from first-principles 29Si NMR analysis

International Nuclear Information System (INIS)

Mauri, Francesco; Pasquarello, Alfredo; Pfrommer, Bernd G.; Yoon, Young-Gui; Louie, Steven G.

2000-01-01

The correlation between 29 Si chemical shifts and Si-O-Si bond angles in SiO 2 is determined within density-functional theory for the full range of angles present in vitreous silica. This relation closely reproduces measured shifts of crystalline polymorphs. The knowledge of the correlation allows us to reliably extract from the experimental NMR spectrum the mean (151 degree sign ) and the standard deviation (11 degree sign ) of the Si-O-Si angular distribution of vitreous silica. In particular, we show that the Mozzi-Warren Si-O-Si angular distribution is not consistent with the NMR data. This analysis illustrates the potential of our approach for structural determinations of silicate glasses. (c) 2000 The American Physical Society

Icefield-to-ocean linkages across the northern Pacific coastal temperate rainforest ecosystem

Science.gov (United States)

O'Neel, Shad; Hood, Eran; Bidlack, Allison L.; Fleming, Sean W.; Arimitsu, Mayumi L.; Arendt, Anthony; Burgess, Evan W.; Sergeant, Christopher J.; Beaudreau, Anne E.; Timm, Kristin; Hayward, Gregory D.; Reynolds, Joel H.; Pyare, Sanjay

2015-01-01

Rates of glacier mass loss in the northern Pacific coastal temperate rainforest (PCTR) are among the highest on Earth, and changes in glacier volume and extent will affect the flow regime and chemistry of coastal rivers, as well as the nearshore marine ecosystem of the Gulf of Alaska. Here we synthesize physical, chemical and biological linkages that characterize the northern PCTR ecosystem, with particular emphasis on the potential impacts of glacier change in the coastal mountain ranges on the surface–water hydrology, biogeochemistry, coastal oceanography and aquatic ecology. We also evaluate the relative importance and interplay between interannual variability and long-term trends in key physical drivers and ecological responses. To advance our knowledge of the northern PCTR, we advocate for cross-disciplinary research bridging the icefield-to-ocean ecosystem that can be paired with long-term scientific records and designed to inform decisionmakers.

Zirconia toughened SiC whisker reinforced alumina composites small business innovation research

Science.gov (United States)

Loutfy, R. O.; Stuffle, K. L.; Withers, J. C.; Lee, C. T.

1987-01-01

The objective of this phase 1 project was to develop a ceramic composite with superior fracture toughness and high strength, based on combining two toughness inducing materials: zirconia for transformation toughening and SiC whiskers for reinforcement, in a controlled microstructure alumina matrix. The controlled matrix microstructure is obtained by controlling the nucleation frequency of the alumina gel with seeds (submicron alpha-alumina). The results demonstrate the technical feasibility of producing superior binary composites (Al2O3-ZrO2) and tertiary composites (Al2O3-ZrO2-SiC). Thirty-two composites were prepared, consolidated, and fracture toughness tested. Statistical analysis of the results showed that: (1) the SiC type is the key statistically significant factor for increased toughness; (2) sol-gel processing with a-alumina seed had a statistically significant effect on increasing toughness of the binary and tertiary composites compared to the corresponding mixed powder processing; and (3) ZrO2 content within the range investigated had a minor effect. Binary composites with an average critical fracture toughness of 6.6MPam sup 1/2, were obtained. Tertiary composites with critical fracture toughness in the range of 9.3 to 10.1 MPam sup 1/2 were obtained. Results indicate that these composites are superior to zirconia toughened alumina and SiC whisker reinforced alumina ceramic composites produced by conventional techniques with similar composition from published data.

Modelling coastal processes and morphological changes of the UK east coast in support of coastal decision-making

Science.gov (United States)

Li, Xiaorong; Leonardi, Nicoletta; Brown, Jennifer; Plater, Andy

2017-04-01

The coastline of Eastern England is home to about one quarter of the UK's coastal habitats, including intertidal salt marshes, tidal flats and sand dunes. These geomorphic features are of great importance to the local wildlife, global biodiversity, marine environment and human society and economy. Due to sea-level rise and the occurrence of extreme weather conditions, the coastline of Eastern England is under high risk of erosion and recession, which could lead to tidal inundation of sites such as the RSPB Minsmere Reserve and power generation infrastructure at Sizewell. This research responds to the need for sustainable shoreline management plans of the UK east coast through sensitivity studies at the Dunwich-Sizewell area, Suffolk, UK. Particular interest is on the long-term morphodynamic response of the study area to possible environmental variations associated with global climate change. Key coastal processes, i.e. current, waves and sediment transport, and morphological evolution are studied using a process-based numerical model under the following scenarios: current mean sea level + calm wave conditions, current mean sea level + storms, sea level rise + calm wave conditions, and sea level rise + storms, all with a 'do nothing' management plan which allows the coastal environment to exist and respond dynamically. As a further aspect of this research, rules will be generalized for reduced-complexity, system-based modelling. Alternative management plans, including 'managed realignment' and 'advance the line', are also investigated in this research under the same environmental forcing scenarios, for the purposes of protection of infrastructure of national importance and conservation of wetland habitats. Both 'hard' and 'soft' engineering options, such as groynes and beach nourishment respectively, are considered. A more ecohydrological option which utilizes aquatic plant communities for wave energy dissipation and sediment trapping is also studied. The last

Interfacial microstructure of NiSi x/HfO2/SiO x/Si gate stacks

International Nuclear Information System (INIS)

Gribelyuk, M.A.; Cabral, C.; Gusev, E.P.; Narayanan, V.

2007-01-01

Integration of NiSi x based fully silicided metal gates with HfO 2 high-k gate dielectrics offers promise for further scaling of complementary metal-oxide- semiconductor devices. A combination of high resolution transmission electron microscopy and small probe electron energy loss spectroscopy (EELS) and energy dispersive X-ray analysis has been applied to study interfacial reactions in the undoped gate stack. NiSi was found to be polycrystalline with the grain size decreasing from top to bottom of NiSi x film. Ni content varies near the NiSi/HfO x interface whereby both Ni-rich and monosilicide phases were observed. Spatially non-uniform distribution of oxygen along NiSi x /HfO 2 interface was observed by dark field Scanning Transmission Electron Microscopy and EELS. Interfacial roughness of NiSi x /HfO x was found higher than that of poly-Si/HfO 2 , likely due to compositional non-uniformity of NiSi x . No intermixing between Hf, Ni and Si beyond interfacial roughness was observed

Protecting biodiversity in coastal environments: Introduction and overview

International Nuclear Information System (INIS)

Beatley, T.

1991-01-01

Much less attention has been paid in recent years to the threats to coastal and marine biodiversity, compared to biodiversity in more terrestrial habitats. The tremendous biodiversity at risk and the severity and magnitude of the pressures being exerted on coastal habitats suggest the need for much greater attention to be focused here by both the policy and scientific communities. The threats to coastal biodiversity are numerous and include air and water pollution; over exploitation and harvesting; the introduction of exotic species; the dramatic loss of habitat due to urbanization, agricultural expansion, and other land use changes; and the potentially serious effects of global climate change. These threats suggest the need for swift action at a number of jurisdictional and governmental levels. Major components of such an effort are identified and described. These include the need for comprehensive management approaches, the expansion of parks and protected areas, restoration and mitigation, multinational and international initiatives, and efforts to promote sustainable development and sustainable lifestyles. Suggestions for future research are also provided

Coastal Economic Trends for Coastal Geographies

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — These market data provide a comprehensive set of measures of changes in economic activity throughout the coastal regions of the United States. In regard to the...

Monolithically Integrated Ge-on-Si Active Photonics

Directory of Open Access Journals (Sweden)

Jifeng Liu

2014-07-01

Full Text Available Monolithically integrated, active photonic devices on Si are key components in Si-based large-scale electronic-photonic integration for future generations of high-performance, low-power computation and communication systems. Ge has become an interesting candidate for active photonic devices in Si photonics due to its pseudo-direct gap behavior and compatibility with Si complementary metal oxide semiconductor (CMOS processing. In this paper, we present a review of the recent progress in Ge-on-Si active photonics materials and devices for photon detection, modulation, and generation. We first discuss the band engineering of Ge using tensile strain, n-type doping, Sn alloying, and separate confinement of Γ vs. L electrons in quantum well (QW structures to transform the material towards a direct band gap semiconductor for enhancing optoelectronic properties. We then give a brief overview of epitaxial Ge-on-Si materials growth, followed by a summary of recent investigations towards low-temperature, direct growth of high crystallinity Ge and GeSn alloys on dielectric layers for 3D photonic integration. Finally, we review the most recent studies on waveguide-integrated Ge-on-Si photodetectors (PDs, electroabsorption modulators (EAMs, and laser diodes (LDs, and suggest possible future research directions for large-scale monolithic electronic-photonic integrated circuits on a Si platform.

The Coastal Hazard Wheel system for coastal multi-hazard assessment & management in a changing climate

DEFF Research Database (Denmark)

Appelquist, Lars Rosendahl; Halsnæs, Kirsten

2015-01-01

This paper presents the complete Coastal Hazard Wheel (CHW) system, developed for multi-hazard-assessment and multi-hazard-management of coastal areas worldwide under a changing climate. The system is designed as a low-tech tool that can be used in areas with limited data availability...... screening and management. The system is developed to assess the main coastal hazards in a single process and covers the hazards of ecosystem disruption, gradual inundation, salt water intrusion, erosion and flooding. The system was initially presented in 2012 and based on a range of test......-applications and feedback from coastal experts, the system has been further refined and developed into a complete hazard management tool. This paper therefore covers the coastal classification system used by the CHW, a standardized assessment procedure for implementation of multi-hazard-assessments, technical guidance...

PENATAAN RUANG LAUT BERDASARKAN INTEGRATED COASTAL MANAGEMENT

Directory of Open Access Journals (Sweden)

Dina Sunyowati

2008-10-01

Full Text Available The planning of coastal spatial arrangement must be put in the valid spatial planning system. Law Number 26 of 2007 on Spatial Planning and it is in fact related with land spatial planning, although that ocean and air spatial management will be arranged in separate law. The legal for coastal zone management is determined by using the principles of integrated coastal management by focusing on area or zone authority system. The integrated of coastal zones management regulations should be followed by the planning of coastal spatial arrange­ment. Therefore, certain synchronization at coastal zones governance is very important issue since by integrating and coordinating other related regulations and therefore conflict of norm can be minimized in the spatial planning coastal zone.

Luminescence properties of Si-capped β-FeSi{sub 2} nanodots epitaxially grown on Si(001) and (111) substrates

Energy Technology Data Exchange (ETDEWEB)

Amari, Shogo; Ichikawa, Masakazu [Department of Applied Physics, Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656 (Japan); Nakamura, Yoshiaki, E-mail: nakamura@ee.es.osaka-u.ac.jp [Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama-cho, Toyonaka, Osaka 560-8531 (Japan); PRESTO, JST, 4-1-8 Honcho Kawaguchi, Saitama 332-0012 (Japan)

2014-02-28

We studied the luminescence properties of Si-capped β-FeSi{sub 2} nanodots (NDs) epitaxially grown on Si substrates by using photoluminescence (PL) and electroluminescence (EL) spectroscopies. Codepositing Fe and Si on ultrathin SiO{sub 2} films induced the self-assembly of epitaxial β-FeSi{sub 2} NDs. The PL spectra of the Si/β-FeSi{sub 2} NDs/Si structure depended on the crystal orientation of the Si substrate. These structures exhibited a broad PL peak near 0.8 eV on both Si(001) and (111) substrates. The PL intensity depended on the shape of the β-FeSi{sub 2} NDs. For the flat NDs, which exhibited higher PL intensity, we also recorded EL spectra. We explained the luminescence properties of these structures by the presence of nanostructured Si offering radiative electronic states in the Si cap layers, generated by nano-stressors for upper Si layer: the strain-relaxed β-FeSi{sub 2} NDs.

Assessing the Sustainable Development of Coastal Reclamation: A Case of Makassar Using GIS Application

Science.gov (United States)

Yurnita, A.; Trisutomo, S.; Ali, M.

2017-07-01

Reclamation has been made in many areas in Indonesia including Makassar, as a response to the present needs of land as the impact of human activity in urban area. This research aims to assess the sustainable development of coastal reclamation and focus on environmental dimension of sustainable urban development. Assessment will be done by reclamation sustainability index (RSI) and analysis by GIS as the tools. RSI was built from previous research that has simplified from many researches and analysis by Structure of Analytic Hierarchy Process (AHP) and expert choice. RSI uses 9 indices from three indicators of environment factor which are coastal resources, building and infrastructure.

Thermal shock properties of 2D-SiCf/SiC composites

International Nuclear Information System (INIS)

Lee, Sang Pill; Lee, Jin Kyung; Son, In Soo; Bae, Dong Su; Kohyama, Akira

2012-01-01

This paper dealt with the thermal shock properties of SiC f /SiC composites reinforced with two dimensional SiC fabrics. SiC f /SiC composites were fabricated by a liquid phase sintering process, using a commercial nano-size SiC powder and oxide additive materials. An Al 2 O 3 –Y 2 O 3 –SiO 2 powder mixture was used as a sintering additive for the consolidation of SiC matrix region. In this composite system, Tyranno SA SiC fabrics were also utilized as a reinforcing material. The thermal shock test for SiC f /SiC composites was carried out at the elevated temperature. Both mechanical strength and microstructure of SiC f /SiC composites were investigated by means of optical microscopy, SEM and three point bending test. SiC f /SiC composites represented a dense morphology with a porosity of about 8.2% and a flexural strength of about 160 MPs. The characterization of SiC f /SiC composites was greatly affected by the history of cyclic thermal shock. Especially, SiC f /SiC composites represented a reduction of flexural strength at the thermal shock temperature difference higher than 800 °C.

SiC/SiC Cladding Materials Properties Handbook

Energy Technology Data Exchange (ETDEWEB)

Snead, Mary A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Katoh, Yutai [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Koyanagi, Takaaki [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Singh, Gyanender P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2017-08-01

When a new class of material is considered for a nuclear core structure, the in-pile performance is usually assessed based on multi-physics modeling in coordination with experiments. This report aims to provide data for the mechanical and physical properties and environmental resistance of silicon carbide (SiC) fiber–reinforced SiC matrix (SiC/SiC) composites for use in modeling for their application as accidenttolerant fuel cladding for light water reactors (LWRs). The properties are specific for tube geometry, although many properties can be predicted from planar specimen data. This report presents various properties, including mechanical properties, thermal properties, chemical stability under normal and offnormal operation conditions, hermeticity, and irradiation resistance. Table S.1 summarizes those properties mainly for nuclear-grade SiC/SiC composites fabricated via chemical vapor infiltration (CVI). While most of the important properties are available, this work found that data for the in-pile hydrothermal corrosion resistance of SiC materials and for thermal properties of tube materials are lacking for evaluation of SiC-based cladding for LWR applications.

Assessing the Nation's Coastal Waters....Better

Science.gov (United States)

The USEPA has been assessing estuarine and coastal condition in the United States since 1999 via the National Coastal Assessment (NCA) and National Aquatic Resources Surveys (NARS) programs. Approximately 1500 randomly selected coastal sites were surveyed annually during summers ...

Black Sea coastal forecasting system

Directory of Open Access Journals (Sweden)

A. I. Kubryakov

2012-03-01

Full Text Available The Black Sea coastal nowcasting and forecasting system was built within the framework of EU FP6 ECOOP (European COastalshelf sea OPerational observing and forecasting system project for five regions: the south-western basin along the coasts of Bulgaria and Turkey, the north-western shelf along the Romanian and Ukrainian coasts, coastal zone around of the Crimea peninsula, the north-eastern Russian coastal zone and the coastal zone of Georgia. The system operates in the real-time mode during the ECOOP project and afterwards. The forecasts include temperature, salinity and current velocity fields. Ecosystem model operates in the off-line mode near the Crimea coast.

National Coastal Condition Report I Factsheet

Science.gov (United States)

The National Coastal Condition Report describes the ecological and environmental conditions in U.S. coastal waters. This first-of-its-kind Report, presents a broad baseline picture of the overall condition of U.S. coastal waters as fair to poor.

Exceptional cracking behavior in H-implanted Si/B-doped Si0.70Ge0.30/Si heterostructures

Science.gov (United States)

Chen, Da; Wang, Dadi; Chang, Yongwei; Li, Ya; Ding, Rui; Li, Jiurong; Chen, Xiao; Wang, Gang; Guo, Qinglei

2018-01-01

The cracking behavior in H-implanted Si/B-doped Si0.70Ge0.30/Si structures after thermal annealing was investigated. The crack formation position is found to closely correlate with the thickness of the buried Si0.70Ge0.30 layer. For H-implanted Si containing a buried 3-nm-thick B-doped Si0.70Ge0.30 layer, localized continuous cracking occurs at the interfaces on both sides of the Si0.70Ge0.30 interlayer. Once the thickness of the buried Si0.70Ge0.30 layer increases to 15 and 70 nm, however, a continuous sharp crack is individually observed along the interface between the Si substrate and the B-doped Si0.70Ge0.30 interlayer. We attribute this exceptional cracking behavior to the existence of shear stress on both sides of the buried Si0.70Ge0.30 layer and the subsequent trapping of hydrogen, which leads to a crack in a well-controlled manner. This work may pave the way for high-quality Si or SiGe membrane transfer in a feasible manner, thus expediting its potential applications to ultrathin silicon-on-insulator (SOI) or silicon-germanium-on-insulator (SGOI) production.

The new Euskalmet coastal-maritime warning system

Science.gov (United States)

Gaztelumendi, Santiago; Egaña, Joseba; Liria, Pedro; Gonzalez, Manuel; Aranda, José Antonio; Anitua, Pedro

2016-06-01

This work presents the main characteristics of the Basque Meteorology Agency (Euskalmet) maritime-coastal risk warning system, with special emphasis on the latest updates, including a clear differentiation on specific warning messages addressing sea conditions for navigation purposes in the first 2 nautical miles, and expected coastal impacts. Some details of the warning bulletin for maritime and coastal risk situations are also presented, together with other communication products and strategies used in coastal and maritime severe episodes at the Basque coast. Today, three different aspects are included in the coastal-maritime risk warning system in Basque Country, related to the main potential severe events that affecting coastal activities. - "Galerna" risk relates to a sudden wind reversal that can severely affect coastal navigation and recreational activities. - "Navigation" risk relates to severe sea state conditions for 0-2 miles, affecting different navigation activities. - "Coastal impact" risk relates to adverse wave characteristics and tidal surges that induce flooding events and different impacts in littoral areas.

Flooding Risk for Coastal Infrastructure: a Stakeholder-Oriented Approach

Science.gov (United States)

Plater, A. J.; Prime, T.; Brown, J. M.; Knight, P. J.; Morrissey, K.

2015-12-01

A flood risk assessment for coastal energy infrastructure in the UK with respect to long-term sea-level rise and extreme water levels has been conducted using a combination of numerical modelling approaches (LISFLOOD-FP, SWAB, XBeach-G, POLCOMS). Model outputs have been incorporated into a decision-support tool that enables users from a wide spectrum of coastal stakeholders (e.g. nuclear energy, utility providers, local government, environmental regulators, communities) to explore the potential impacts of flooding on both operational (events to 10 years) and strategic (10 to 50 years) timescales. Examples illustrate the physical and economic impacts of flooding from combined extreme water levels, wave overtopping and high river flow for Fleetwood, NW England; changes in the extent of likely flooding arising from an extreme event due to sea-level rise for Oldbury, SW England; and the relative vulnerability to overtopping and breaching of sea defences for Dungeness, SE England. The impacts of a potential large-scale beach recharge scheme to mitigate coastal erosion and flood risk along the southern shoreline of Dungeness are also examined using a combination of coastal evolution and particle-tracking modelling. The research goal is to provide an evidence base for resource allocation, investment in interventions, and communication and dialogue in relation to sea-level rise to 2500 AD.

Visualization of Coastal Data Through KML

Science.gov (United States)

Damsma, T.; Baart, F.; de Boer, G.; van Koningsveld, M.; Bruens, A.

2009-12-01

As a country that lies mostly below sea level, the Netherlands has a history of coastal engineering, and is world renowned for its leading role in Integrated Coastal Zone Management (ICZM). Within the framework of Building with Nature (a Dutch ICZM research program) an OPeNDAP server is used to host several datasets of the Dutch coast. Among these sets are bathymetric data, cross-shore profiles, water level time series of which some date back to the eighteenth century. The challenge with hosting this amount of data is more in dissemination and accessibility rather than a technical one (tracing, accessing, gathering, unifying and storing). With so many data in different sets, how can one easily know when and where data is available, and of what quality it is? Recent work using Google Earth as a visual front-end for this database has proven very encouraging. Taking full advantage of the four dimensional (3D+time) visualization capabilities allows researchers, consultants and the general public to view, access and interact with the data. Within MATLAB a set of generic tools are developed for easy creation of among others: A high resolution, time animated, historic bathymetry of the entire Dutch coast. 3D curvilinear computation grids. A 3D contour plot of the Westerschelde Estuary. Time animated wind and water flow fields, both with traditional quiver diagrams and arrows that move with the flow field. Various overviews of markers containing direct web links to data and metadata on OPeNDAP server. Wind field (arrows) and water level elevation for model calculations of Katrina (animated over 14 days) Coastal cross sections (with exaggerated hight) and 2D positions of high and low water lines (animated over 40 years)

Temperature dependence of dark current of pSi-n(Si2)1-x(CdS)x structures

International Nuclear Information System (INIS)

Usmonov, Sh.N.

2007-01-01

Full text: The research of influence of isovalent impurity on electric and photo-electric properties of semiconductors where formative with semiconductor continuous solid solutions (CSS) of substitution presents both the fundamental and the applied application interest at the area of material science and photoelectrical properties of semiconductors. In the given work results of experimental researches (Si 2 ) 1-x (CdS) x epitaxial layers grown on c-Si substrates by a method liquid phase epitaxy are presented. The grown layers had thickness and ∼ 10 micron, n-type of conductivity with specific resistance 0,016 Ohm sm. Dependences of the dark current of pSi-n(Si 2 ) 1-x (CdS) x structures have been investigated at various values of a bias voltage. In experiment it was observed anomaly dependence of current. The current with arising of temperature begun monotonously aroused and reached some minimal value at temperature 100 C and then again starts to arise up to temperature 200 C. Arising of dark current is caused of the band-to-band thermal generation of electron-hole pairs. The voltage drop at the temperature 100 C is caused by the recharging of impurity atoms CdS. It is known, that width of the forbidden band of CdS Eg,CdS=2,48 eV more than Eg,Si=1,1 eV. Covalent bond of atoms CdS is stronger than Si-Si bond. However, when the molecule of CdS replaces two atoms of silicon in tetrahedral lattice of silicon the bonds of Cd-S become weak under influence of surrounding atoms of silicon. It causes to occurrence impurity level CdS located on Ei=1,2 eV below a valence band top of silicon. The generation of electron-hole pairs with participation of CdS impurities at the 100 C temperature is occurred under action thermal phonons. However, holes formed on impurity levels are localized and they will be recombination centers. Therefore drop of the dark current caused by dispersion of carriers on impurity centers. (authors)

The Southern California Coastal Ocean Observing System (SCCOOS): Developing A Coastal Observation System To Enable Both Science Based Decision Making And Scientific Discovery

Science.gov (United States)

Terrill, E.; John, O.

2005-05-01

The Southern California Coastal Ocean Observing System (SCCOOS) is a consortium that extends from Northern Baja CA in Mexico to Morro Bay at the southern edge of central California, and aims to streamline, coordinate, and further develop individual institutional efforts by creating an integrated, multidisciplinary coastal observatory in the Bight of Southern California for the benefit of society. By leveraging existing infrastructure, partnerships, and private, local, state, and federal resources, SCCOOS is developing a fully operational coastal observation system to address issues related to coastal water quality, marine life resources, and coastal hazards for end user communities spanning local, state, and federal interests. However, to establish a sensible observational approach to address these societal drivers, sound scientific approaches are required in both the system design and the transformation of data to useful products. Since IOOS and coastal components of the NSF Ocean Observatories Initiative (OOI) are not mutually exclusive within this framework, the SCCOOS consortium of observatory implementers have created an organizational structure that encourages dovetailing of OOI into the routine observations provided by the operational components of a regional IOOS. To begin the development, SCCOOS has grant funding from the California Coastal Conservancy as part of a $21M, statewide initiative to establish a Coastal Ocean Currents Monitoring Program, and funding from NOAA's Coastal Observing Technology System (COTS). In addition, SCCOOS is leveraging IT development that has been supported by the NSF Information Technology Research program Real-time observatories, Applications,and Data Manageemnt Network (ROADNET), and anticipates using developments which will result from the NSF Laboratory for Ocean Observatory Knowledge Integration Grid (LOOKING) program. The observational components now funded at SCCOOS include surface current mapping by HF radar; high

Sintering Behavior of Spark Plasma Sintered SiC with Si-SiC Composite Nanoparticles Prepared by Thermal DC Plasma Process

Science.gov (United States)

Yu, Yeon-Tae; Naik, Gautam Kumar; Lim, Young-Bin; Yoon, Jeong-Mo

2017-11-01

The Si-coated SiC (Si-SiC) composite nanoparticle was prepared by non-transferred arc thermal plasma processing of solid-state synthesized SiC powder and was used as a sintering additive for SiC ceramic formation. Sintered SiC pellet was prepared by spark plasma sintering (SPS) process, and the effect of nano-sized Si-SiC composite particles on the sintering behavior of micron-sized SiC powder was investigated. The mixing ratio of Si-SiC composite nanoparticle to micron-sized SiC was optimized to 10 wt%. Vicker's hardness and relative density was increased with increasing sintering temperature and holding time. The relative density and Vicker's hardness was further increased by reaction bonding using additional activated carbon to the mixture of micron-sized SiC and nano-sized Si-SiC. The maximum relative density (97.1%) and Vicker's hardness (31.4 GPa) were recorded at 1800 °C sintering temperature for 1 min holding time, when 0.2 wt% additional activated carbon was added to the mixture of SiC/Si-SiC.

Coastal sensitivity mapping of Gulf of Kachchh and Gulf of Cambay, India

Digital Repository Service at National Institute of Oceanography (India)

ManiMurali, R.; Boora, P.; Vethamony, P.

and managers of coastal zones are also useful for identifying sensitive resources before a spill occurs (Jenson, 1998). In this way, protection priorities could be identified and established and cleanup strategies could be designed in advance. To deal... regions to oil spills. This research focuses on improving information about coastal environment mapping from remote sensing and GIS technology to generate maps of environmental sensitivity index for oil spill in Gulf of Kachchh and Gulf of Cambay...

Knowledge, Attitudes and Practices of Coastal Communities on Waste Management in Ghana

OpenAIRE

Essuman, Nasir

2017-01-01

Waste management has been a worldwide issue which most countries are finding the best ways of dealing with. Managing waste improperly poses threat to the health of individuals and the environment. Ghana as a developing country, its coastal communities are faced with a lot of challenges regarding waste management due to actions towards waste management. This research seeks to examine the knowledge, attitudes and practices of coastal communities on waste management and how their actions have a...

Coastal erosion problem, modelling and protection

Science.gov (United States)

Yılmaz, Nihal; Balas, Lale; İnan, Asu

2015-09-01

Göksu Delta, located in the south of Silifke County of Mersin on the coastal plain formed by Göksu River, is one of the Specially Protected Areas in Turkey. Along the coastal area of the Delta, coastline changes at significant rates are observed, concentrating especially at four regions; headland of İncekum, coast of Paradeniz Lagoon, river mouth of Göksu and coast of Altınkum. The coast of Paradeniz Lagoon is suffering significantly from erosion and the consequent coastal retreating problem. Therefore, the narrow barrier beach which separates Paradeniz Lagoon from the Mediterranean Sea is getting narrower, creating a risk of uniting with the sea, thus causing the disappearance of the Lagoon. The aim of this study was to understand the coastal transport processes along the coastal area of Göksu Delta to determine the coastal sediment transport rates, and accordingly, to propose solutions to prevent the loss of coastal lands in the Delta. To this end, field measurements of currents and sediment grain sizes were carried out, and wind climate, wave climate, circulation patterns and longshore sediment transport rates were numerically modeled by HYDROTAM-3D, which is a three dimensional hydrodynamic transport model. Finally, considering its special importance as an environmentally protected region, some coastal structures of gabions were proposed as solutions against the coastal erosion problems of the Delta. The effects of proposed structures on future coastline changes were also modeled, and the coastlines predicted for the year 2017 are presented and discussed in the paper.

Application of Long Distance Conveyance (LDC) of Dredged Sediments to Louisiana Coastal Restoration

Science.gov (United States)

2011-01-01

generally use some type of bucket for digging the sediment, then hoist or boom the load to the surface. Most common hydraulic methods use a centrifugal...sediment. The loaded bucket is hoisted to the surface and side dumped into a transportation unit, or into the disposal site. Transportation units are...Conveyance (LDC) of Dredged Sediments to Louisiana Coastal Restoration Timothy Welp Coastal and Hydraulics Laboratory U.S. Army Engineer Research

The coastal transportation in Brazil - potential for the improvement of aiming intermodality logistic flow

Directory of Open Access Journals (Sweden)

Delmo Alves Moura

2011-06-01

Full Text Available This study describes aspects related to coastal shipping in Brazil and its main actors and intermodal factors (road, rail, fluvial transportation etc. which corroborate to the increase of logistics competitiveness and efficiency of transportation in a large country like Brazil. The purpose of the study is bibliographic research on the topic, analyzing it inside the Brazilian scenario and also how it has been implemented in some countries. The objective of the study is also analyzing legislation which defines parameters to coastal shipping. This fact interferes directly with the logistics system and its intermodal aspects. If Brazil intends to reduce its logistics costs, coastal shipping should be an effective way to contribute to the Brazilian matrix of transport. Coastal shipping is supposed to bring competitive advantage and reduction of logistic costs. The conclusion is that integration is essential among the systems of domestic transportation and coastal shipping with its outstanding role in this environment, can contribute substantially to the Brazilian maritime industry.

Macroclimatic change expected to transform coastal wetland ecosystems this century

Science.gov (United States)

Gabler, Christopher A.; Osland, Michael J.; Grace, James B.; Stagg, Camille L.; Day, Richard H.; Hartley, Stephen B.; Enwright, Nicholas M.; From, Andrew S.; McCoy, Meagan L.; McLeod, Jennie L.

2017-01-01

Coastal wetlands, existing at the interface between land and sea, are highly vulnerable to climate change. Macroclimate (for example, temperature and precipitation regimes) greatly influences coastal wetland ecosystem structure and function. However, research on climate change impacts in coastal wetlands has concentrated primarily on sea-level rise and largely ignored macroclimatic drivers, despite their power to transform plant community structure and modify ecosystem goods and services. Here, we model wetland plant community structure based on macroclimate using field data collected across broad temperature and precipitation gradients along the northern Gulf of Mexico coast. Our analyses quantify strongly nonlinear temperature thresholds regulating the potential for marsh-to-mangrove conversion. We also identify precipitation thresholds for dominance by various functional groups, including succulent plants and unvegetated mudflats. Macroclimate-driven shifts in foundation plant species abundance will have large effects on certain ecosystem goods and services. Based on current and projected climatic conditions, we project that transformative ecological changes are probable throughout the region this century, even under conservative climate scenarios. Coastal wetland ecosystems are functionally similar worldwide, so changes in this region are indicative of potential future changes in climatically similar regions globally.

The sociological perspective in coastal management and geoengineering approach: effects of hydraulic structures on the resilience of fishing communities (NW Portugal)

Science.gov (United States)

Rocha, Fernando; Pires, Ana; Chamine, Helder

2014-05-01

The coast plays an important role in global transportation and is the most popular tourist destination around the world. During the years coastal scientists "walking on the shore", have tried to understand the shoreline in relation to the processes that shape it, and its interrelationships with the contiguous superficial marine and terrestrial hinterland environments. Those factors encourage the need for Integrated Coastal Zone Management (ICZM), because of its possible use in identifying coastal management issues to take into account in policy strategies, measures and planning. Therefore this research presents an integrated strategy and a holistic approach to researching and studying coastal areas involving a wide number of sciences including sociology. Because of the numerous types of hazards in coastal areas the only possible response involves a holistic, integrated and long term approach. Combining marine sociological research, resilience and flexibility of a particular coastal community with other scientific fields will help to understand and manage marine social problems. This study also shows an integrative and "eclectic" methodology and adapts it to coastal management. Hence a new integrated coastal geoengineering approach for maritime environments was proposed, which is the core foundation of this approach. Also it was important to incorporate in a broader sense coastal geosciences and geoengineering GIS mapping to this final equation resulting in conceptual models. In Portugal there are several areas buffeted by sea invasions, coastal erosion and severe storms. The Portuguese coastal zone is one of Europe's most vulnerable regarding coastal erosion. The case study presented herein is an example of one of the most vulnerable sites in Portugal in terms of coastal erosion and sea invasions and how the meeting of local fishing community and coastal projects are extremely important. The coastal stretch between Figueira da Foz and Espinho (Centre and NW

Electrical properties of Si/Si1-xGex/Si inverted modulation doped structures

International Nuclear Information System (INIS)

Sadeghzadeh, M.A.

1998-12-01

This thesis is a report of experimental investigations of growth strategy and electrical properties of Si/Si 1-x Ge x /Si inverted Modulation Doped (MD) structures grown by solid source Molecular Beam Epitaxy (MBE). If the grown Si layer is B-doped at some distance (as spacer) before or after the alloy layer, this remote doping induces the formation of a quasi Two Dimensional Hole Gas (2-DHG) near to the inverted (SiGe on Si) or normal (Si on SiGe) heterointerfaces of the Si/Si 1-x Ge x /Si quantum well, respectively. The latter arrangement is the well known 'normal' MD structure but the former one is the so-called 'inverted' MD structure which is of great interest for Field Effect Transistor (FET) applications. A reproducible growth strategy was employed by the use of a thick (400nm) Si cap for inverted MD structures with Ge composition in the range of 16-23%. Boron segregation and cap surface charges are significant in these inverted structures with small ( 20nm) spacer layers, respectively. It was demonstrated by secondary ion mass spectroscopy (SIMS) that boron segregation, which causes a reduction in the effective spacer dimension, can be suppressed by growth interruption after boron doping. The enhancement in hole sheet density with increasing Si cap layer thickness, is attributed to a reduction in the influence of positive surface charges in these structures. Top-gated devices were fabricated using these structures and the hole sheet density could be varied by applying a voltage to the metal-semiconductor gate, and the maximum Hall mobility of 5550 cm 2 V -1 s -1 with 4.2x10 11 cm -2 was measured (at 1.6K) in these structures. Comparison of measured Hall mobility (at 4.2K) as a function of hole sheet density in normal and inverted MD structures implies that both 2-DHG confined at normal and/or inverted structures are subjected to very similar interface charge, roughness, and alloy scattering potentials. Low temperatures magnetotransport measurements (down to

Abrupt GaP/Si hetero-interface using bistepped Si buffer

Energy Technology Data Exchange (ETDEWEB)

Ping Wang, Y., E-mail: yanping.wang@insa-rennes.fr; Kuyyalil, J.; Nguyen Thanh, T.; Almosni, S.; Bernard, R.; Tremblay, R.; Da Silva, M.; Létoublon, A.; Rohel, T.; Tavernier, K.; Le Corre, A.; Cornet, C.; Durand, O. [UMR FOTON, CNRS, INSA Rennes, Rennes F-35708 (France); Stodolna, J.; Ponchet, A. [CEMES-CNRS, Université de Toulouse, 29 rue Jeanne Marvig, BP 94347, 31055 Toulouse Cedex 04 (France); Bahri, M.; Largeau, L.; Patriarche, G. [Laboratoire de Photonique et Nanostructures, CNRS UPR 20, Route de Nozay, Marcoussis 91460 (France); Magen, C. [LMA, INA-ARAID, and Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50018 Zaragoza (Spain)

2015-11-09

We evidence the influence of the quality of the starting Si surface on the III-V/Si interface abruptness and on the formation of defects during the growth of III-V/Si heterogeneous crystal, using high resolution transmission electron microscopy and scanning transmission electron microscopy. GaP layers were grown by molecular beam epitaxy on vicinal Si (001). The strong effect of the Si substrate chemical preparation is first demonstrated by studying structural properties of both Si homoepitaxial layer and GaP/Si heterostructure. It is then shown that choosing adequate chemical preparation conditions and subsequent III-V regrowth conditions enables the quasi-suppression of micro-twins in the epilayer. Finally, the abruptness of GaP/Si interface is found to be very sensitive to the Si chemical preparation and is improved by the use of a bistepped Si buffer prior to III-V overgrowth.

Abrupt GaP/Si hetero-interface using bistepped Si buffer

International Nuclear Information System (INIS)

Ping Wang, Y.; Kuyyalil, J.; Nguyen Thanh, T.; Almosni, S.; Bernard, R.; Tremblay, R.; Da Silva, M.; Létoublon, A.; Rohel, T.; Tavernier, K.; Le Corre, A.; Cornet, C.; Durand, O.; Stodolna, J.; Ponchet, A.; Bahri, M.; Largeau, L.; Patriarche, G.; Magen, C.

2015-01-01

We evidence the influence of the quality of the starting Si surface on the III-V/Si interface abruptness and on the formation of defects during the growth of III-V/Si heterogeneous crystal, using high resolution transmission electron microscopy and scanning transmission electron microscopy. GaP layers were grown by molecular beam epitaxy on vicinal Si (001). The strong effect of the Si substrate chemical preparation is first demonstrated by studying structural properties of both Si homoepitaxial layer and GaP/Si heterostructure. It is then shown that choosing adequate chemical preparation conditions and subsequent III-V regrowth conditions enables the quasi-suppression of micro-twins in the epilayer. Finally, the abruptness of GaP/Si interface is found to be very sensitive to the Si chemical preparation and is improved by the use of a bistepped Si buffer prior to III-V overgrowth

Street Geometry Factors Influence Urban Microclimate in Tropical Coastal Cities: A Review

Directory of Open Access Journals (Sweden)

Shafaghat Arezou

2016-05-01

Full Text Available Urban climatologists have moved smoothly towards urban geometry meso-scales as obstruction between buildings, streets, and urban environment. Urban climatologists and designers have expressed that urban geometry parameters affect urban microclimate conditions. Improper functioning of the geometry factors, particularly air temperature and wind speed, can increase the harshness of climate change and Urban Heat Island (UHI defects, which are more critical in coastal cities of tropical regions. In this regard, the current study aimed to identify the impact of each street geometry factor on urban microclimate through a critical literature review. The research determined a total of twenty seven (27 factors within three clusters; 1 geometry factors, 2 meteorological factors, and 3 streetscape factors. The content analysis calculated the Depth of Citation (DoC which refers to the cumulative importance level of each factor. The content analysis resulted air temperature (Ta (DoC = 18 out of 28 is the most important street geometry factor that should be extensively considered in urban microclimate studies in coastal cities. In contrast, the factors (such as air pollution and traffic load have received a minimum Doc (1 out of 28. The research has also analyzed the importance level of clusters through an expert input study using Grounded Group Decision Making (GGDM method. The results show that meteorological cluster (92 %, streetscape cluster (86 %, and geometry cluster (85 % have to be respectively implemented in urban microclimate studies in coastal cities. The research states there are new approaches have not yet been touched by urban climatologist affecting urban microclimate; included; surface materials, sea-borne dust and sand, user’s satisfaction, user’s thermal adaptive behavior. These approaches can potentially exacerbate UHI effects in coastal cities, which need further research.

Synthesis and structural property of Si nanosheets connected to Si nanowires using MnCl{sub 2}/Si powder source

Energy Technology Data Exchange (ETDEWEB)

Meng, Erchao [Graduate School of Science and Technology, Shizuoka University, 3-5-1 Johuku, Naka-ku, Hamamatsu, Shizuoka 432-8561 (Japan); Ueki, Akiko [Toyota Central R& D Labs., Inc., 41-1 Yokomichi, Nagakute, Aichi 480-1192 (Japan); Meng, Xiang [Graduate School of Science and Technology, Shizuoka University, 3-5-1 Johuku, Naka-ku, Hamamatsu, Shizuoka 432-8561 (Japan); Suzuki, Hiroaki [Graduate School of Engineering, Shizuoka University, 3-5-1 Johuku, Naka-ku, Hamamatsu, Shizuoka 432-8561 (Japan); Itahara, Hiroshi [Toyota Central R& D Labs., Inc., 41-1 Yokomichi, Nagakute, Aichi 480-1192 (Japan); Tatsuoka, Hirokazu, E-mail: tatsuoka.hirokazu@shizuoka.ac.jp [Graduate School of Integrated Science and Technology, Shizuoka University, 3-5-1 Johuku, Naka-ku, Hamamatsu, Shizuoka 432-8561 (Japan)

2016-08-15

Graphical abstract: Si nanosheets connected to Si nanowires synthesized using a MnCl{sub 2}/Si powder source with an Au catalyst avoid the use of air-sensitive SiH{sub 4} or SiCl{sub 4}. It was evident from these structural features of the nanosheets (leaf blade) with nanowires (petiole) that the nanosheets were formed by the twin-plane reentrant-edge mechanism. The feature of the observed lattice fringes of the Si(111) nanosheets was clearly explained by the interference with the extra diffraction spots that arose due to the reciprocal lattice streaking effect. - Highlights: • New Si nanosheets connected to Si nanowires were synthesized using MnCl{sub 2}/Si powders. • The synthesis method has benefits in terms of avoiding air sensitive SiH{sub 4} or SiCl{sub 4}. • Structural property and electron diffraction of the Si nanosheets were clarified. • Odd lattice fringes of the Si nanosheets observed by HRTEM were clearly explained. - Abstract: Si nanosheets connected to Si nanowires were synthesized using a MnCl{sub 2}/Si powder source with an Au catalyst. The synthesis method has benefits in terms of avoiding conventionally used air-sensitive SiH{sub 4} or SiCl{sub 4}. The existence of the Si nanosheets connected to the Si<111> nanowires, like sprouts or leaves with petioles, was observed, and the surface of the nanosheets was Si{111}. The nanosheets were grown in the growth direction of <211> perpendicular to that of the Si nanowires. It was evident from these structural features of the nanosheets that the nanosheets were formed by the twin-plane reentrant-edge mechanism. The feature of the observed lattice fringes, which do not appear for Si bulk crystals, of the Si(111) nanosheets obtained by high resolution transmission electron microscopy was clearly explained due to the extra diffraction spots that arose by the reciprocal lattice streaking effect.

Research of morphology and structure of 3C–SiC thin films on silicon by electron microscopy and X-ray diffractometry

Directory of Open Access Journals (Sweden)

Alexander S. Gusev

2015-12-01

Full Text Available Thin films of silicon carbide possessing unique properties attract increasing attention of researchers both in the field of semiconductor physics and in the technology of new semiconductor devices for high power, RF and optoelectronics. The growth of the production of silicon carbide based devices promotes the search for more resource saving and safe SiC layer synthesis technologies. Potential method is pulse laser deposition (PLD in vacuum. This technology does not require the use of chemically aggressive and explosive gases and allows forming thin and continuous coatings with thicknesses of from several nanometers at relatively low substrate temperatures. Submicron thickness silicon carbide films have been grown on single crystal silicon by vacuum laser ablation of a ceramic target. The physical and technological parameters of silicon carbide thin film low temperature synthesis by PLD have been studied and, in particular, the effect of temperature and substrate crystalline orientation on the composition, structural properties and morphology of the surface of the experimental specimens has been analyzed. At above 500 °C the crystalline β-SiC phase forms on Si (100 and (111. At a substrate temperature of 950 °C the formation of textured heteroepitaxial 3C–SiC films was observed.

Recent progress in GeSi electro-absorption modulators

International Nuclear Information System (INIS)

Chaisakul, Papichaya; Marris-Morini, Delphine; Rouifed, Mohamed-Said; Coudevylle, Jean-René; Roux, Xavier Le; Edmond, Samson; Vivien, Laurent; Frigerio, Jacopo; Chrastina, Daniel; Isella, Giovanni

2014-01-01

Electro-absorption from GeSi heterostructures is receiving growing attention as a high performance optical modulator for short distance optical interconnects. Ge incorporation with Si allows strong modulation mechanism using the Franz–Keldysh effect and the quantum-confined Stark effect from bulk and quantum well structures at telecommunication wavelengths. In this review, we discuss the current state of knowledge and the on-going challenges concerning the development of high performance GeSi electro-absorption modulators. We also provide feasible future prospects concerning this research topic. (review)

Sintering Behavior of Spark Plasma Sintered SiC with Si-SiC Composite Nanoparticles Prepared by Thermal DC Plasma Process.

Science.gov (United States)

Yu, Yeon-Tae; Naik, Gautam Kumar; Lim, Young-Bin; Yoon, Jeong-Mo

2017-11-25

The Si-coated SiC (Si-SiC) composite nanoparticle was prepared by non-transferred arc thermal plasma processing of solid-state synthesized SiC powder and was used as a sintering additive for SiC ceramic formation. Sintered SiC pellet was prepared by spark plasma sintering (SPS) process, and the effect of nano-sized Si-SiC composite particles on the sintering behavior of micron-sized SiC powder was investigated. The mixing ratio of Si-SiC composite nanoparticle to micron-sized SiC was optimized to 10 wt%. Vicker's hardness and relative density was increased with increasing sintering temperature and holding time. The relative density and Vicker's hardness was further increased by reaction bonding using additional activated carbon to the mixture of micron-sized SiC and nano-sized Si-SiC. The maximum relative density (97.1%) and Vicker's hardness (31.4 GPa) were recorded at 1800 °C sintering temperature for 1 min holding time, when 0.2 wt% additional activated carbon was added to the mixture of SiC/Si-SiC.

Coastal Hazards: Hurricanes, Tsunamis, Coastal Erosion.

Science.gov (United States)

Vandas, Steve

1998-01-01

Details an ocean-based lesson and provides background information on the designation of 1998 as the "Year of the Ocean" by the United Nations. Contains activities on the poster insert that can help raise student awareness of coastal-zone hazards. (DDR)

Role of yttria-stabilized zirconia produced by ion-beam-assisted deposition on the properties of RuO2 on SiO2/Si

International Nuclear Information System (INIS)

Jia, Q.X.; Arendt, P.; Groves, J.R.; Fan, Y.; Roper, J.M.; Foltyn, S.R.

1998-01-01

Highly conductive biaxially textured RuO 2 thin films were deposited on technically important SiO 2 /Si substrates by pulsed laser deposition, where yttria-stabilized zirconia (YSZ) produced by ion-beam-assisted-deposition (IBAD) was used as a template to enhance the biaxial texture of RuO 2 on SiO 2 /Si. The biaxially oriented RuO 2 had a room-temperature resistivity of 37 μΩ-cm and residual resistivity ratio above 2. We then deposited Ba 0.5 Sr 0.5 TiO 3 thin films on RuO 2 /IBAD-YSZ/SiO 2 /Si. The Ba 0.5 Sr 0.5 TiO 3 had a pure (111) orientation normal to the substrate surface and a dielectric constant above 360 at 100 kHz. copyright 1998 Materials Research Society

Formation, structure, and phonon confinement effect of nanocrystalline Si1-xGex in SiO2-Si-Ge cosputtered films

International Nuclear Information System (INIS)

Yang, Y.M.; Wu, X.L.; Siu, G.G.; Huang, G.S.; Shen, J.C.; Hu, D.S.

2004-01-01

Using magnetron cosputtering of SiO 2 , Ge, and Si targets, Si-based SiO 2 :Ge:Si films were fabricated for exploring the influence of Si target proportion (P Si ) and annealing temperature (Ta) on formation, local structure, and phonon properties of nanocrystalline Si 1-x Ge x (nc-Si 1-x Ge x ). At low P Si and Ta higher than 800 deg. C, no nc-Si 1-x Ge x but a kind of composite nanocrystal consisting of a Ge core, GeSi shell, and amorphous Si outer shell is formed in the SiO 2 matrix. At moderate P Si , nc-Si 1-x Ge x begins to be formed at Ta=800 deg. C and coexists with nc-Ge at Ta=1100 deg. C. At high P Si , it was disclosed that both optical phonon frequency and lattice spacing of nc-Si 1-x Ge x increase with raising Ta. The possible origin of this phenomenon is discussed by considering three factors, the phonon confinement, strain effect, and composition variation of nc-Si 1-x Ge x . This work will be helpful in understanding the growth process of ternary GeSiO films and beneficial to further investigations on optical properties of nc-Ge 1-x Si x in the ternary matrix

Si/SiGe heterointerfaces in one-, two-, and three-dimensional nanostructures: their impact on SiGe light emission

Science.gov (United States)

Lockwood, David; Wu, Xiaohua; Baribeau, Jean-Marc; Mala, Selina; Wang, Xialou; Tsybeskov, Leonid

2016-03-01

Fast optical interconnects together with an associated light emitter that are both compatible with conventional Si-based complementary metal-oxide- semiconductor (CMOS) integrated circuit technology is an unavoidable requirement for the next-generation microprocessors and computers. Self-assembled Si/Si1-xGex nanostructures, which can emit light at wavelengths within the important optical communication wavelength range of 1.3 - 1.55 μm, are already compatible with standard CMOS practices. However, the expected long carrier radiative lifetimes observed to date in Si and Si/Si1-xGex nanostructures have prevented the attainment of efficient light-emitting devices including the desired lasers. Thus, the engineering of Si/Si1-xGex heterostructures having a controlled composition and sharp interfaces is crucial for producing the requisite fast and efficient photoluminescence (PL) at energies in the range 0.8-0.9 eV. In this paper we assess how the nature of the interfaces between SiGe nanostructures and Si in heterostructures strongly affects carrier mobility and recombination for physical confinement in three dimensions (corresponding to the case of quantum dots), two dimensions (corresponding to quantum wires), and one dimension (corresponding to quantum wells). The interface sharpness is influenced by many factors such as growth conditions, strain, and thermal processing, which in practice can make it difficult to attain the ideal structures required. This is certainly the case for nanostructure confinement in one dimension. However, we demonstrate that axial Si/Ge nanowire (NW) heterojunctions (HJs) with a Si/Ge NW diameter in the range 50 - 120 nm produce a clear PL signal associated with band-to-band electron-hole recombination at the NW HJ that is attributed to a specific interfacial SiGe alloy composition. For three-dimensional confinement, the experiments outlined here show that two quite different Si1-xGex nanostructures incorporated into a Si0.6Ge0.4 wavy

The Abudance Of Makrozoobenthos On Different Break Water In Semarang And Demak Coastal Area

Science.gov (United States)

Kristiningsih, A.; Sugianto, D. N.; Munasik; Pribadi, R.; Suprijanto, J.

2018-02-01

The coast of Semarang and Demak has suffered some damage to its coastal areas. This damage is caused by natural factors and also human activities. There are number of mitigation methods such as hard, soft and hybrid that available for mitigation erosion. In Semarang and Demak coastal area using hard and hybrid option as their mitigation erotion. Breakwater is one of the way beach structure that often used as mitigation erosion di coastal area. Breakwater will cause sediment deposits that will become the living place of various organisms such as makrozoobenthos. The aim of this research is compare the abudance of makrozoobenthos in different type breakwater in Semarang and Demak coastal area.This research held on December 2016 - January 2017 in five different location with different breakwater type. Hard structure in Mangkang (West Semarang), Morosari (Demak district) and Tambak Lorok (North Semarang) and the hybrid engineering in Morosari 2 (Demak district) and Timbulsloko (Demak district). The method used in this study is descriptive comparative. Makrozoobenthos has been found in each station and the highest indeks is in hybrid engineering location. Polychaeta is a genus that dominates at every location because muddy sand is its main habitat.

Experimental and thermodynamic assessments of substitutions in the AlFeSi, FeMnSi, FeSiZr and AlCaFeSi systems (65 wt % Si) - solidification simulation

International Nuclear Information System (INIS)

Gueneau, C.; Ansara, I.

1994-01-01

The substitutions of Al Si, Fe Mn and Fe Zr in some intermetallic compounds of the Al-Fe-Si, Fe-Mn-Si and Fe-Si-Zr systems are modelled in the Si-rich corner using a two sublattice model. The solidification paths of the studied alloys are determined at equilibrium. The ascalculated phase volume fractions of the alloys are compared to the experimental ones. Finally, a solidification simulation using the Gulliver-Scheil's model is performed in order to explain the formation of some precipitates experimentally observed. (authors). 14 figs., 19 refs

76 FR 37761 - Fisheries Off West Coast States; Coastal Pelagic Species Fisheries; Amendment 13 to the Coastal...

Science.gov (United States)

2011-06-28

.... 110606318-1319-01] RIN 0648-BA68 Fisheries Off West Coast States; Coastal Pelagic Species Fisheries; Amendment 13 to the Coastal Pelagic Species Fishery Management Plan; Annual Catch Limits AGENCY: National... the Coastal Pelagic Species (CPS) Fishery Management Plan (FMP). This proposed rule will implement...

76 FR 33189 - Fisheries Off West Coast States; Coastal Pelagic Species Fisheries; Amendment 13 to the Coastal...

Science.gov (United States)

2011-06-08

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration 50 CFR Part 660 RIN 0648-BA68 Fisheries Off West Coast States; Coastal Pelagic Species Fisheries; Amendment 13 to the Coastal... Pacific Fishery Management Council (Council) has submitted Amendment 13 to the Coastal Pelagic Species...

Ultrathin SiO{sub 2} layer formed by the nitric acid oxidation of Si (NAOS) method to improve the thermal-SiO{sub 2}/Si interface for crystalline Si solar cells

Energy Technology Data Exchange (ETDEWEB)

Matsumoto, Taketoshi; Nakajima, Hiroki; Irishika, Daichi; Nonaka, Takaaki; Imamura, Kentaro; Kobayashi, Hikaru, E-mail: h.kobayashi@sanken.osaka-u.ac.jp

2017-02-15

Highlights: • The density of interface states at the SiO{sub 2}/Si interface is decreased by NAOS. • The minority carrier lifetime is increased by the NAOS treatment. • Great interfacial properties of the NAOS layer are kept after thermal oxidation. - Abstract: A combination of the nitric acid oxidation of Si (NAOS) method and post-thermal oxidation is found to efficiently passivate the SiO{sub 2}/n-Si(100) interface. Thermal oxidation at 925 °C and annealing at 450 °C in pure hydrogen atmosphere increases the minority carrier lifetime by three orders of magnitude, and it is attributed to elimination of Si dangling bond interface states. Fabrication of an ultrathin, i.e., 1.1 nm, NAOS SiO{sub 2} layer before thermal oxidation and H{sub 2} annealing further increases the minority carrier lifetime by 30% from 8.6 to 11.1 ms, and decreased the interface state density by 10% from 6.9 × 10{sup 9} to 6.3 × 10{sup 9}eV{sup −1} cm{sup −2}. After thermal oxidation at 800 °C, the SiO{sub 2} layer on the NAOS-SiO{sub 2}/Si(100) structure is 2.26 nm thick, i.e., 0.24 nm thicker than that on the Si(100) surface, while after thermal oxidation at 925 °C, it is 4.2 nm thick, i.e., 0.4 nm thinner than that on Si(100). The chemical stability results from the higher atomic density of a NAOS SiO{sub 2} layer than that of a thermal oxide layer as reported in Ref. [28] (Asuha et al., 2002). Higher minority carrier lifetime in the presence of the NAOS layer indicates that the NAOS-SiO{sub 2}/Si interface with a low interface state density is preserved after thermal oxidation, which supports out-diffusion oxidation mechanism, by which a thermal oxide layer is formed on the NAOS SiO{sub 2} layer.

Comparing the engineering program feeders from SiF and convention models

Science.gov (United States)

Roongruangsri, Warawaran; Moonpa, Niwat; Vuthijumnonk, Janyawat; Sangsuwan, Kampanart

2018-01-01

This research aims to compare the relationship between two types of engineering program feeder models within the technical education systems of Rajamangala University of Technology Lanna (RMUTL), Chiangmai, Thailand. To illustrate, the paper refers to two typologies of feeder models, which are the convention and the school in factory (SiF) models. The new SiF model is developed through a collaborative educational process between the sectors of industry, government and academia, using work-integrated learning. The research methodology were use to compared features of the the SiF model with conventional models in terms of learning outcome, funding budget for the study, the advantages and disadvantages from the point of view of students, professors, the university, government and industrial partners. The results of this research indicate that the developed SiF feeder model is the most pertinent ones as it meet the requirements of the university, the government and the industry. The SiF feeder model showed the ability to yield positive learning outcomes with low expenditures per student for both the family and the university. In parallel, the sharing of knowledge between university and industry became increasingly important in the process, which resulted in the improvement of industrial skills for professors and an increase in industrial based research for the university. The SiF feeder model meets its demand of public policy in supporting a skilled workforce for the industry, which could be an effective tool for the triple helix educational model of Thailand.

Squeeze Casting Method Of AI-Si Alloy For Piston Material

International Nuclear Information System (INIS)

Wagiyo, H.; Dani, Muhammad; Sulistioso, G.S.; Pardede, Elman; Handayani, Ari; Teguh, Yulius S.P.P.

2001-01-01

The AI-Si alloy is an alloy used as piston material. This alloys could be as AI-Si hypereutectic alloy (Si content more than 12.5 % wt.), as AI-Si eutectic alloy (Si cuntent 12.5 % wt, and as AI-Si hypoeutectic alloy (Si content less than 12.5 % wt.). The synthesize of AI-Si alloy piston generally using the technique of gravity casting in a dies. This method is causing high porousity. By using the squeeze technique, amount ofporousity in AI-Si alloy is possibly reduced and the density of this alloy should be higher. The other factors such as alloying elements of AI-Si alloy (Mg. Cu, Zn) would increase the mechanical properties especially the hardness. The focuses of this research are the microstructure and the maximum hardness during the heat treatment of AI-Si alloy which was added by alloying elments. The result of hardness at test shows the maximum hardness at 94.7 kg/mm 2 obtained at aging temperature of 210 o C for hours with homogenous dendritic microstructure

Comparison of interfaces for (Ba,Sr)TiO3 films deposited on Si and SiO2/Si substrates

International Nuclear Information System (INIS)

Suvorova, N.A.; Lopez, C.M.; Irene, E.A.; Suvorova, A.A.; Saunders, M.

2004-01-01

(Ba,Sr)TiO 3 (BST) thin films were deposited by ion sputtering on both bare and oxidized Si. Spectroscopic ellipsometry results have shown that a SiO 2 underlayer of nearly the same thickness (2.6 nm in average) is found at the Si interface for BST sputter depositions onto nominally bare Si, 1 nm SiO 2 on Si or 3.5 nm SiO 2 on Si. This result was confirmed by high-resolution electron microscopy analysis of the films, and it is believed to be due to simultaneous subcutaneous oxidation of Si and reaction of the BST layer with SiO 2 . Using the conductance method, capacitance-voltage measurements show a decrease in the interface trap density D it of an order of magnitude for oxidized Si substrates with a thicker SiO 2 underlayer. Further reduction of D it was achieved for the capacitors grown on oxidized Si and annealed in forming gas after metallization

Comparison of interfaces for (Ba,Sr)TiO3 films deposited on Si and SiO2/Si substrates

Science.gov (United States)

Suvorova, N. A.; Lopez, C. M.; Irene, E. A.; Suvorova, A. A.; Saunders, M.

2004-03-01

(Ba,Sr)TiO3(BST) thin films were deposited by ion sputtering on both bare and oxidized Si. Spectroscopic ellipsometry results have shown that a SiO2 underlayer of nearly the same thickness (2.6 nm in average) is found at the Si interface for BST sputter depositions onto nominally bare Si, 1 nm SiO2 on Si or 3.5 nm SiO2 on Si. This result was confirmed by high-resolution electron microscopy analysis of the films, and it is believed to be due to simultaneous subcutaneous oxidation of Si and reaction of the BST layer with SiO2. Using the conductance method, capacitance-voltage measurements show a decrease in the interface trap density Dit of an order of magnitude for oxidized Si substrates with a thicker SiO2 underlayer. Further reduction of Dit was achieved for the capacitors grown on oxidized Si and annealed in forming gas after metallization.

Eastern Africa Coastal Forest Programme

OpenAIRE

Younge, A.

2002-01-01

The eastern African coastal forest ecoregion is recognised as one of Africa’s centres of species endemism, and is distributed over six countries (Somalia, Kenya, Tanzania, Mozambique, Zimbabwe and Malawi). Most is found in Kenya, Tanzania and Mozambique, which form our focal region. The coastal forests are fragmented, small and surrounded by poor communities that have a high demand for land and forest resources. Although coastal forests have significant cultural and traditional...

Mechanical behavior of SiCf/SiC composites with alternating PyC/SiC multilayer interphases

International Nuclear Information System (INIS)

Yu, Haijiao; Zhou, Xingui; Zhang, Wei; Peng, Huaxin; Zhang, Changrui

2013-01-01

Highlights: ► Superior combination of flexural strength and fracture toughness of the 3D SiC/SiC composite was achieved by interface tailoring. ► Resulted composite possesses a much higher flexural strength and fracture toughness than its counterparts in literatures. ► Mechanisms that PyC/SiC multilayer coatings improve the mechanical properties were illustrated. -- Abstract: In order to tailor the fiber–matrix interface of continuous silicon carbide fiber reinforced silicon carbide (SiC f /SiC) composites for improved fracture toughness, alternating pyrolytic carbon/silicon carbide (PyC/SiC) multilayer coatings were applied to the KD-I SiC fibers using chemical vapor deposition (CVD) method. Three dimensional (3D) KD-I SiC f /SiC composites reinforced by these coated fibers were fabricated using a precursor infiltration and pyrolysis (PIP) process. The interfacial characteristics were determined by the fiber push-out test and microstructural examination using scanning electron microscopy (SEM). The effect of interface coatings on composite mechanical properties was evaluated by single-edge notched beam (SENB) test and three-point bending test. The results indicate that the PyC/SiC multilayer coatings led to an optimum interfacial bonding between fibers and matrix and greatly improved the fracture toughness of the composites.

Oscillations in the fusion of the Si + Si systems

International Nuclear Information System (INIS)

Aguilera R, E.F.; Kolata, J.J.; DeYoung, P.A.; Vega, J.J.

1986-02-01

Excitation functions for the yields of all the residual nuclei from the 28 Si + 28,30 and 30 Si + 30 Si reactions have been measured via the γ-ray technique for center of mass energies in the region within one and two times the Coulomb barrier.Thirteen elements were identified for the first reaction and ten for the other two. While no structure is shown by the data for the 28 + 28 Si reaction, we have found evidence for intermediate width structure in the 2α and the αpn channels in 28 Si + 30 Si and for broad structure in the total fusion cross sections for 30 Si + 30 Si. Calculations using a barrier penetration model with one free parameter reproduce the experimental results quite well. Evaporation model calculations indicate that the individual structure of the nuclei involved in the respective decay chains might have an important influence upon the deexcitation process at the energies relevant to our experiments. (Author)

27 CFR 9.207 - Outer Coastal Plain.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Outer Coastal Plain. 9.207... Outer Coastal Plain. (a) Name. The name of the viticultural area described in this section is “Outer Coastal Plain”. For purposes of part 4 of this chapter, “Outer Coastal Plain” is a term of viticultural...

Environmental Barrier Coating Development for SiC/SiC Ceramic Matrix Composites: Recent Advances and Future Directions

Science.gov (United States)

Zhu, Dongming

2016-01-01

This presentation briefly reviews the SiC/SiC major environmental and environment-fatigue degradations encountered in simulated turbine combustion environments, and thus NASA environmental barrier coating system evolution for protecting the SiC/SiC Ceramic Matrix Composites for meeting the engine performance requirements. The presentation will review several generations of NASA EBC materials systems, EBC-CMC component system technologies for SiC/SiC ceramic matrix composite combustors and turbine airfoils, highlighting the temperature capability and durability improvements in simulated engine high heat flux, high pressure, high velocity, and with mechanical creep and fatigue loading conditions. This paper will also focus on the performance requirements and design considerations of environmental barrier coatings for next generation turbine engine applications. The current development emphasis is placed on advanced NASA candidate environmental barrier coating systems for SiC/SiC CMCs, their performance benefits and design limitations in long-term operation and combustion environments. The efforts have been also directed to developing prime-reliant, self-healing 2700F EBC bond coat; and high stability, lower thermal conductivity, and durable EBC top coats. Major technical barriers in developing environmental barrier coating systems, the coating integrations with next generation CMCs having the improved environmental stability, erosion-impact resistance, and long-term fatigue-environment system durability performance will be described. The research and development opportunities for turbine engine environmental barrier coating systems by utilizing improved compositions, state-of-the-art processing methods, and simulated environment testing and durability modeling will be briefly discussed.

NOAA's Coastal Change Analysis Program (C-CAP) 2010 Forest Fragmentation Data - Coastal United States

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Coastal Change Analysis Program (C-CAP) produces national standardized land cover and change products for the coastal regions of the U.S. C-CAP products...

NOAA's Coastal Change Analysis Program (C-CAP) 2006 Forest Fragmentation Data - Coastal United States

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Coastal Change Analysis Program (C-CAP) produces national standardized land cover and change products for the coastal regions of the U.S. C-CAP products...

NOAA's Coastal Change Analysis Program (C-CAP) 1985 Forest Fragmentation Data - Coastal United States

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Coastal Change Analysis Program (C-CAP) produces national standardized land cover and change products for the coastal regions of the U.S. C-CAP products...

NOAA's Coastal Change Analysis Program (C-CAP) 1996 Forest Fragmentation Data - Coastal United States

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Coastal Change Analysis Program (C-CAP) produces national standardized land cover and change products for the coastal regions of the U.S. C-CAP products...

Structure of MnSi on SiC(0001)

Science.gov (United States)

Meynell, S. A.; Spitzig, A.; Edwards, B.; Robertson, M. D.; Kalliecharan, D.; Kreplak, L.; Monchesky, T. L.

2016-11-01

We report on the growth and magnetoresistance of MnSi films grown on SiC(0001) by molecular beam epitaxy. The growth resulted in a textured MnSi(111) film with a predominantly [1 1 ¯0 ] MnSi (111 )∥[11 2 ¯0 ] SiC(0001) epitaxial relationship, as demonstrated by transmission electron microscopy, reflection high energy electron diffraction, and atomic force microscopy. The 500 ∘C temperature required to crystallize the film leads to a dewetting of the MnSi layer. Although the sign of the lattice mismatch suggested the films would be under compressive stress, the films acquire an in-plane tensile strain likely driven by the difference in thermal expansion coefficients between the film and substrate during annealing. As a result, the magnetoresistive response demonstrates that the films possess a hard-axis out-of-plane magnetocrystalline anisotropy.

Coastal Zone Color Scanner studies

Science.gov (United States)

Elrod, J.

1988-01-01

Activities over the past year have included cooperative work with a summer faculty fellow using the Coastal Zone Color Scanner (CZCS) imagery to study the effects of gradients in trophic resources on coral reefs in the Caribbean. Other research included characterization of ocean radiances specific to an acid-waste plume. Other activities include involvement in the quality control of imagery produced in the processing of the global CZCS data set, the collection of various other data global sets, and the subsequent data comparison and analysis.

FEM for modelling 193 nm excimer laser treatment of SiO{sub 2}/Si/Si{sub (1-x)}Ge{sub x} heterostructures on SOI substrates

Energy Technology Data Exchange (ETDEWEB)

Conde, J.C.; Chiussi, S.; Gontad, F.; Gonzalez, P. [Dpto. Fisica Aplicada, E.T.S.I.I. University of Vigo, Campus Universitario, Rua Maxwell s/n, 36310 Vigo (Spain); Martin, E. [Dpto. de Mecanica, Maquinas, Motores Termicos y Fluidos, E.T.S.I.I. University of Vigo, Campus Universitario, Rua Maxwell s/n, 36310 Vigo (Spain)

2011-03-15

Research on epitaxial crystalline silicon (c-Si) and silicon-germanium (Si{sub 1-x}Ge{sub x}) alloys growth and annealing for microelectronic purposes, such as Micro- or Nano-Electro-Mechanical Systems (MEMS or NEMS) and Silicon-On-Nothing (SON) devices is continuously in progress. Laser assisted annealing techniques using commercial ArF Excimer Laser sources are based on ultra-rapid heating and cooling cycles induced by the 193 nm pulses of 20 ns, which are absorbed in the near surface region of the heterostructures. During and after the absorption of these laser pulses, complex physical processes appear that strongly depend on sample structure and applied laser pulse energy densities. The control of the experimental parameters is therefore a key task for obtaining high quality alloys. The Finite ElementsMethod (FEM) is a powerful tool for the optimization of such treatments, because it provides the spatial and temporal temperature fields that are produced by the laser pulses. In this work, we have used a FEM commercial software, to predict the temperatures gradients induced by ArF excimer laser over a wide energy densities range, 0.1<{phi}<0.4 J/cm{sup 2}, on different SiO{sub 2}/Si/Si{sub (1-x)}Ge{sub (x)} thin films deposited on SOI substrate. These numerical results allow us to predict the threshold energies needed to reach the melting point (MP) of the Si and SiGe alloy without oxidation of the thin films system. Therefore, it is possible to optimize the conditions to achieve high quality epitaxy films. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Analysis of Unmanned Aerial Vehicle (UAV) hyperspectral remote sensing monitoring key technology in coastal wetland

Science.gov (United States)

Ma, Yi; Zhang, Jie; Zhang, Jingyu

2016-01-01

The coastal wetland, a transitional zone between terrestrial ecosystems and marine ecosystems, is the type of great value to ecosystem services. For the recent 3 decades, area of the coastal wetland is decreasing and the ecological function is gradually degraded with the rapid development of economy, which restricts the sustainable development of economy and society in the coastal areas of China in turn. It is a major demand of the national reality to carry out the monitoring of coastal wetlands, to master the distribution and dynamic change. UAV, namely unmanned aerial vehicle, is a new platform for remote sensing. Compared with the traditional satellite and manned aerial remote sensing, it has the advantage of flexible implementation, no cloud cover, strong initiative and low cost. Image-spectrum merging is one character of high spectral remote sensing. At the same time of imaging, the spectral curve of each pixel is obtained, which is suitable for quantitative remote sensing, fine classification and target detection. Aimed at the frontier and hotspot of remote sensing monitoring technology, and faced the demand of the coastal wetland monitoring, this paper used UAV and the new remote sensor of high spectral imaging instrument to carry out the analysis of the key technologies of monitoring coastal wetlands by UAV on the basis of the current situation in overseas and domestic and the analysis of developing trend. According to the characteristic of airborne hyperspectral data on UAV, that is "three high and one many", the key technology research that should develop are promoted as follows: 1) the atmosphere correction of the UAV hyperspectral in coastal wetlands under the circumstance of complex underlying surface and variable geometry, 2) the best observation scale and scale transformation method of the UAV platform while monitoring the coastal wetland features, 3) the classification and detection method of typical features with high precision from multi scale

Flow-structure-seabed interactions in coastal and marine environments

DEFF Research Database (Denmark)

Sumer, B. Mutlu

2014-01-01

Flow–structure–seabed interaction in coastal and marine environments is a rapidly growing area of research and applications. In this vision paper, this area is discussed with a view of identifying its state of the art and current research challenges. The discussion draws attention to key issues......, among other areas, as an emerging branch of Marine Civil Engineering. Predictions of the field development for the forthcoming years are also briefly outlined....

Towards a management perspective for coastal upwelling ecosystems

Energy Technology Data Exchange (ETDEWEB)

Howe, S.O.; Walsh, J.J.

1976-01-01

Data are reviewed from studies on the general distribution of upwelling of coastal waters, associated current patterns, and first order biological effects. Field observations and theory are discussed. Recent research has shown that variability and dynamism are the predominant characteristic features of these regions. Populations related by nonlinear interactions occur in constantly moving patches and swirls subjected to variability in the winds, currents, water chemistry, and solar insolation. Gross stationary features of upwelling communities have been described, but the responses of critical components and their relationships to human or natural perturbations remain poorly defined in this and other types of coastal ecosystems. Large scale research programs recognize that the continental shelf ecosystems are complex event-oriented phenomena. It is postulated that assessment of living resources in an environmental vacuum may lead to mismanagement and hindcasting rather than prescient management. A growing data base encourages the development of computer simulation models of ecosystem relationships and responses will lead to better understanding and management of these and other marine ecosystems in the future. 80 references.

Comparative performance of PV panels of different technologies over one year of exposure: Application to a coastal Mediterranean region of Algeria

International Nuclear Information System (INIS)

Guenounou, A.; Malek, A.; Aillerie, M.

2016-01-01

Highlights: • Performances of four PV panels of various technologies are compared during one year of exposure under natural outdoor conditions. • An original platform and methodology of test allow a real-time scan of several PV panel parameters. • The technologies compared are micromorph silicon, monocrystalline silicon, amorphous silicon, polycrystalline silicon. • The performance ratio point out a difference of behavior between the four technologies over one year. • Results are directly exploitable in costal regions of Mediterranean countries. - Abstract: The aim of this contribution is to compare the performance of four PV panels of different technologies for one year of exposure under natural outdoor conditions of a coastal region in the southern shore of the Mediterranean Sea. An original platform of test, especially dedicated for this study is presented describing operations and techniques used for measurements of the pertinent experimental data and for their exploitation. The four panel technologies studied are micromorph silicon (μ-Si), monocrystalline silicon (M-Si), amorphous silicon (a-Si) and polycrystalline silicon (Poli-Si). Two types of results are analyzed and presented. The first type is straight forwardly linked to the PV panels standard data calculated experimentally from measurements recorded during one year of exposure and compared with the values provided by the manufacturers in their datasheets. The second type is related to the energy yield in which the corresponding monthly and annual performance ratios of the four PV panels is calculated in two ways, using 1 – the datasheet’s value of Power Max, and 2 – the data providing from experimental campaign. In addition to the general conclusions concerning the fundamental role of the experimental study at a natural site for a good sizing of a renewable energy production system, we extend the analysis and discussion for the specific localization case of southern coastal region of

Laser-controlled stress of Si nanocrystals in a free-standing Si /SiO2 superlattice

Science.gov (United States)

Khriachtchev, Leonid; Räsänen, Markku; Novikov, Sergei

2006-01-01

We report laser manipulations with stress at the nanoscale level. The continuous-wave Ar+ laser radiation melts Si nanocrystals in a free-standing Si /SiO2 superlattice. Silicon crystallization from the liquid phase leads to a compressive stress, which can be accurately tuned in the 3GPa range using laser annealing below the Si melting temperature and then recovered by laser annealing above the melting temperature. This allows investigations of various phenomena as a function of stress and makes a case of Si-nanocrystal memory with very long retention time, which can be written, erased, and read by optical means.

Laser-controlled stress of Si nanocrystals in a free-standing Si/SiO2 superlattice

International Nuclear Information System (INIS)

Khriachtchev, Leonid; Raesaenen, Markku; Novikov, Sergei

2006-01-01

We report laser manipulations with stress at the nanoscale level. The continuous-wave Ar + laser radiation melts Si nanocrystals in a free-standing Si/SiO 2 superlattice. Silicon crystallization from the liquid phase leads to a compressive stress, which can be accurately tuned in the 3 GPa range using laser annealing below the Si melting temperature and then recovered by laser annealing above the melting temperature. This allows investigations of various phenomena as a function of stress and makes a case of Si-nanocrystal memory with very long retention time, which can be written, erased, and read by optical means

Isotopic effects in sub-barrier fusion of Si + Si systems

Science.gov (United States)

Colucci, G.; Montagnoli, G.; Stefanini, A. M.; Esbensen, H.; Bourgin, D.; Čolović, P.; Corradi, L.; Faggian, M.; Fioretto, E.; Galtarossa, F.; Goasduff, A.; Grebosz, J.; Haas, F.; Mazzocco, M.; Scarlassara, F.; Stefanini, C.; Strano, E.; Szilner, S.; Urbani, M.; Zhang, G. L.

2018-04-01

Background: Recent measurements of fusion cross sections for the 28Si+28Si system revealed a rather unsystematic behavior; i.e., they drop faster near the barrier than at lower energies. This was tentatively attributed to the large oblate deformation of 28Si because coupled-channels (CC) calculations largely underestimate the 28Si+28Si cross sections at low energies, unless a weak imaginary potential is applied, probably simulating the deformation. 30Si has no permanent deformation and its low-energy excitations are of a vibrational nature. Previous measurements of this system reached only 4 mb, which is not sufficient to obtain information on effects that should show up at lower energies. Purpose: The aim of the present experiment was twofold: (i) to clarify the underlying fusion dynamics by measuring the symmetric case 30Si+30Si in an energy range from around the Coulomb barrier to deep sub-barrier energies, and (ii) to compare the results with the behavior of 28Si+28Si involving two deformed nuclei. Methods: 30Si beams from the XTU tandem accelerator of the Laboratori Nazionali di Legnaro of the Istituto Nazionale di Fisica Nucleare were used, bombarding thin metallic 30Si targets (50 μ g /cm2) enriched to 99.64 % in mass 30. An electrostatic beam deflector allowed the detection of fusion evaporation residues (ERs) at very forward angles, and angular distributions of ERs were measured. Results: The excitation function of 30Si+30Si was measured down to the level of a few microbarns. It has a regular shape, at variance with the unusual trend of 28Si+28Si . The extracted logarithmic derivative does not reach the LCS limit at low energies, so that no maximum of the S factor shows up. CC calculations were performed including the low-lying 2+ and 3- excitations. Conclusions: Using a Woods-Saxon potential the experimental cross sections at low energies are overpredicted, and this is a clear sign of hindrance, while the calculations performed with a M3Y + repulsion

Southern Alaska Coastal Relief Model

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's National Geophysical Data Center (NGDC) is building coastal-relief models (CRM) for select U.S. coastal regions. Bathymetric, topographic, and shoreline data...

Analyzing coastal turbidity under complex terrestrial loads characterized by a 'stress connectivity matrix' with an atmosphere-watershed-coastal ocean coupled model

Science.gov (United States)

Yamamoto, Takahiro; Nadaoka, Kazuo

2018-04-01

Atmospheric, watershed and coastal ocean models were integrated to provide a holistic analysis approach for coastal ocean simulation. The coupled model was applied to coastal ocean in the Philippines where terrestrial sediment loads provided from several adjacent watersheds play a major role in influencing coastal turbidity and are partly responsible for the coastal ecosystem degradation. The coupled model was validated using weather and hydrologic measurement to examine its potential applicability. The results revealed that the coastal water quality may be governed by the loads not only from the adjacent watershed but also from the distant watershed via coastal currents. This important feature of the multiple linkages can be quantitatively characterized by a "stress connectivity matrix", which indicates the complex underlying structure of environmental stresses in coastal ocean. The multiple stress connectivity concept shows the potential advantage of the integrated modelling approach for coastal ocean assessment, which may also serve for compensating the lack of measured data especially in tropical basins.

Self-aligned indium–gallium–zinc oxide thin-film transistors with SiNx/SiO2/SiNx/SiO2 passivation layers

International Nuclear Information System (INIS)

Chen, Rongsheng; Zhou, Wei; Zhang, Meng; Kwok, Hoi-Sing

2014-01-01

Self-aligned top-gate amorphous indium–gallium–zinc oxide (a-IGZO) thin-film transistors (TFTs) with SiN x /SiO 2 /SiN x /SiO 2 passivation layers are developed in this paper. The resulting a-IGZO TFT exhibits high reliability against bias stress and good electrical performance including field-effect mobility of 5 cm 2 /Vs, threshold voltage of 2.5 V, subthreshold swing of 0.63 V/decade, and on/off current ratio of 5 × 10 6 . With scaling down of the channel length, good characteristics are also obtained with a small shift of the threshold voltage and no degradation of subthreshold swing. The proposed a-IGZO TFTs in this paper can act as driving devices in the next generation flat panel displays. - Highlights: • Self-aligned top-gate indium–gallium–zinc oxide thin-film transistor is proposed. • SiN x /SiO 2 /SiN x /SiO 2 passivation layers are developed. • The source/drain areas are hydrogen-doped by CHF3 plasma. • The devices show good electrical performance and high reliability against bias stress

Extended abstracts from the Coastal Habitats in Puget Sound (CHIPS) 2006 Workshop

Science.gov (United States)

Gelfenbaum, Guy R.; Fuentes, Tracy L.; Duda, Jeffrey J.; Grossman, Eric E.; Takesue, Renee K.

2010-01-01

Puget Sound is the second largest estuary in the United States. Its unique geology, climate, and nutrient-rich waters produce and sustain biologically productive coastal habitats. These same natural characteristics also contribute to a high quality of life that has led to a significant growth in human population and associated development. This population growth, and the accompanying rural and urban development, has played a role in degrading Puget Sound ecosystems, including declines in fish and wildlife populations, water-quality issues, and loss and degradation of coastal habitats.In response to these ecosystem declines and the potential for strategic large-scale preservation and restoration, a coalition of local, State, and Federal agencies, including the private sector, Tribes, and local universities, initiated the Puget Sound Nearshore Ecosystem Restoration Project (PSNERP). The Nearshore Science Team (NST) of PSNERP, along with the U.S. Geological Survey, developed a Science Strategy and Research Plan (Gelfenbaum and others, 2006) to help guide science activities associated with nearshore ecosystem restoration. Implementation of the Research Plan includes a call for State and Federal agencies to direct scientific studies to support PSNERP information needs. In addition, the overall Science Strategy promotes greater communication with decision makers and dissemination of scientific results to the broader scientific community.On November 14–16, 2006, the U.S. Geological Survey sponsored an interdisciplinary Coastal Habitats in Puget Sound (CHIPS) Research Workshop at Fort Worden State Park, Port Townsend, Washington. The main goals of the workshop were to coordinate, integrate, and link research on the nearshore of Puget Sound. Presented research focused on three themes: (1) restoration of large river deltas; (2) recovery of the nearshore ecosystem of the Elwha River; and (3) effects of urbanization on nearshore ecosystems. The more than 35 presentations

Coastal wetland adaptation to sea level rise: Quantifying potential for landward migration and coastal squeeze

Science.gov (United States)

Borchert, Sinéad M.; Osland, Michael J.; Enwright, Nicholas M.; Griffith, Kereen

2018-01-01

Coastal wetland ecosystems are expected to migrate landwards in response to rising seas. However, due to differences in topography and coastal urbanization, estuaries vary in their ability to accommodate migration. Low‐lying urban areas can constrain migration and lead to wetland loss (i.e. coastal squeeze), especially where existing wetlands cannot keep pace with rising seas via vertical adjustments. In many estuaries, there is a pressing need to identify landward migration corridors and better quantify the potential for landward migration and coastal squeeze.We quantified and compared the area available for landward migration of tidal saline wetlands and the area where urban development is expected to prevent migration for 39 estuaries along the wetland‐rich USA Gulf of Mexico coast. We did so under three sea level rise scenarios (0.5, 1.0, and 1.5 m by 2100).Within the region, the potential for wetland migration is highest within certain estuaries in Louisiana and southern Florida (e.g. Atchafalaya/Vermilion Bays, Mermentau River, Barataria Bay, and the North and South Ten Thousand Islands estuaries).The potential for coastal squeeze is highest in estuaries containing major metropolitan areas that extend into low‐lying lands. The Charlotte Harbor, Tampa Bay, and Crystal‐Pithlachascotee estuaries (Florida) have the highest amounts of urban land expected to constrain wetland migration. Urban barriers to migration are also high in the Galveston Bay (Texas) and Atchafalaya/Vermilion Bays (Louisiana) estuaries.Synthesis and applications. Coastal wetlands provide many ecosystem services that benefit human health and well‐being, including shoreline protection and fish and wildlife habitat. As the rate of sea level rise accelerates in response to climate change, coastal wetland resources could be lost in areas that lack space for landward migration. Migration corridors are particularly important in highly urbanized estuaries where, due to low‐lying coastal

Introduction to the Special Issue: Coastal GIS

Directory of Open Access Journals (Sweden)

Timothy Nyerges

2014-09-01

Full Text Available This special issue of the ISPRS International Journal of Geographic Information about “Coastal GIS” is motivated by many circumstances. More than one-half of the world’s human population lives in coastal areas (within 200 kilometers of coast as of 2000 [1]. The trend toward coastal habitation is expected to continue in the US with the total being 75 percent by 2025, meaning that coastal human–environment interactions will likely increase and intensify [2]. Geographic information systems (GIS are being developed and used by technical specialists, stakeholder publics, and executive/policy decision makers for improving our understanding and management of coastal areas, separately and together as more organizations focus on improving the sustainability and resilience of coastal systems. Coastal systems—defined as the area of land closely connected to the sea, including barrier islands, wetlands, mudflats, beaches, estuaries, cities, towns, recreational areas, and maritime facilities, the continental seas and shelves, and the overlying atmosphere—are subject to complex and dynamic interactions among natural and human-driven processes. Coastal systems are crucial to regional and national economies, hosting valued human-built infrastructure and providing ecosystem services that sustain human well-being. This special issue of IJGI about coastal GIS presents a collection of nine papers that address many of the issues mentioned above. [...

Synthesis and characterization of laminated Si/SiC composites

Science.gov (United States)

Naga, Salma M.; Kenawy, Sayed H.; Awaad, Mohamed; Abd El-Wahab, Hamada S.; Greil, Peter; Abadir, Magdi F.

2012-01-01

Laminated Si/SiC ceramics were synthesized from porous preforms of biogenous carbon impregnated with Si slurry at a temperature of 1500 °C for 2 h. Due to the capillarity infiltration with Si, both intrinsic micro- and macrostructure in the carbon preform were retained within the final ceramics. The SEM micrographs indicate that the final material exhibits a distinguished laminar structure with successive Si/SiC layers. The produced composites show weight gain of ≈5% after heat treatment in air at 1300 °C for 50 h. The produced bodies could be used as high temperature gas filters as indicated from the permeability results. PMID:25685404

Synthesis and characterization of laminated Si/SiC composites

Directory of Open Access Journals (Sweden)

Salma M. Naga

2013-01-01

Full Text Available Laminated Si/SiC ceramics were synthesized from porous preforms of biogenous carbon impregnated with Si slurry at a temperature of 1500 °C for 2 h. Due to the capillarity infiltration with Si, both intrinsic micro- and macrostructure in the carbon preform were retained within the final ceramics. The SEM micrographs indicate that the final material exhibits a distinguished laminar structure with successive Si/SiC layers. The produced composites show weight gain of ≈5% after heat treatment in air at 1300 °C for 50 h. The produced bodies could be used as high temperature gas filters as indicated from the permeability results.

Propagation of misfit dislocations from buffer/Si interface into Si

Science.gov (United States)

Liliental-Weber, Zuzanna [El Sobrante, CA; Maltez, Rogerio Luis [Porto Alegre, BR; Morkoc, Hadis [Richmond, VA; Xie, Jinqiao [Raleigh, VA

2011-08-30

Misfit dislocations are redirected from the buffer/Si interface and propagated to the Si substrate due to the formation of bubbles in the substrate. The buffer layer growth process is generally a thermal process that also accomplishes annealing of the Si substrate so that bubbles of the implanted ion species are formed in the Si at an appropriate distance from the buffer/Si interface so that the bubbles will not migrate to the Si surface during annealing, but are close enough to the interface so that a strain field around the bubbles will be sensed by dislocations at the buffer/Si interface and dislocations are attracted by the strain field caused by the bubbles and move into the Si substrate instead of into the buffer epi-layer. Fabrication of improved integrated devices based on GaN and Si, such as continuous wave (CW) lasers and light emitting diodes, at reduced cost is thereby enabled.

U.S. Coastal Flood Damage Reduction Projects: Federal Authorization and Investment Trends

Science.gov (United States)

Carter, N. T.

2015-12-01

The 2015 U.S. Environmental Protection Agency report Climate Change in the United States: Benefits of Global Action estimated the potential cumulative future economic impacts of storm surge and sea-level rise on U.S. coasts during this century at 5 trillion (2014 dollars) if no adaptation measures are implemented. These impacts drop to 0.8 trillion if investments are made in cost-effective adaptations and protections. Awareness of flood risk and its long-term fiscal impact historically has proven insufficient to motivate pre-disaster land use changes and investments in mitigation and protection. While many adaptations and protections fall largely under state and local authority, some stakeholders are interested in federal coastal flood protection projects, including projects by the U.S. Army Corps of Engineers. Since the 1950s, Congress has authorized the Corps to construct specific coastal projects. The broad vision, strategy, and priorities for the federal role in coastal flood damage reduction projects nonetheless remain ill-defined. This research analyzes (1) the authorization and appropriations trends for Corps coastal storm damage reduction projects, and (2) how Corps feasibility studies account for and address coastal flood hazards. Identified trends include: emergency appropriations for storm-damaged areas outstrip annual investments in coastal flood projects; the rate at which projects are congressionally approved for construction outpaces the rate at which construction is funded; and how coastal protection projects are evaluated in Corps feasibility studies shows variation and change in agency practices. These trends have consequences; they affect public and local expectations when projects begin providing protection benefits, and may influence investments in other adaptation measures. These trends also raise questions for policymakers at all levels and for scientists and practitioners interested in coastal flood resilience.